[Standard] World War Z (Deck). Input Needed Please.

Well, to put things in perspective I am one of the older players.  I remember when Armageddon and Serra angel where the wombo combo.  People could play mox's and duel lands were in every deck.  It was the best of times, It was the worst of times

This rarely happens due to net decking.  You still have to be a competent player.  My store is very competitive, 30+ people, tier 1 decks, rogue tier 2 decks. It runs the gambit, I don't know how your store is, but if it's even half as competitive as mine then "sweeping" an FNM with a tournament deck isn't very likely at all. In fact playing JUND I've never made 1st place, 2nd once, 3-4 a few, 6-8 a few more times and when we go six rounds for a top 12 pay out , I've done that a couple times.

I can respect wanting to brew your own build, it's fun and it's part of the game, but as a married father of 4, I don't have time to do the testing that's necessary to brew my own build.  You literally need dozens of test matches or more to make sure your card choices are valid against the other tier 1 decks out there.  If you can't beat american and Jund right now then your deck probably won't fair very well.  Netdecking is a good way to find decks and save yourself some time.  Ultimately once you start evaluating why they make the choices in the decks and how everything plays in the meta, the deck starts to be come inevitable, as if there isn't another way for the deck to play and evolve.  I say let the deck doctors do their work, and as long as we understand the methods behind their madness then we shouldn't feel bad about emulating their wisdom.  That's not to say you can' slap something together for fun, but we shouldn't expect to do better than the pros at constructing competitive decks.

I would say, if you want to brew, do it on the side while you play a more competitive deck until your sure your brew is worthy.  A friend and I try this every now and then.  You really need someone to help you test and work out the kinks before you take it to a tournament.

Tutoring - Okay, here's how it goes.  Statistically, tutoring is very effective you're 100% like to get the card you tutor for at a substantial cost of 4 mana.  This severely hurts your tempo, at a 4 mana sorcery, you have to play it on your turn and the advantage for finding the card quickly becomes nullified by your tempo loss.   This huge investment is such a draw back that it's not worth it.  Let me try to explain.

Lets say you curve out in your original build.

Starting hand, crawler, ghoul, reaver, tutor, 3 lands, you draw into the lands and the blockade the rest of the turns.

Turn 1: Grave Crawler
Turn 2: butcher ghoul
Turn 3: Corpse blockade
Turn 4: Tutor - for mikaus
Turn 5: Liliana's Reaver
Turn 6: Mikaeus

That's great, you curved out, but remember zombies are low costed and aggressively positioned for a reason.  Assuming you got to attack and do damage you're looking at, maybe 20 damage on turn 6 if you're opponent just plays land every turn and does nothing. In this meta that's way too slow for just combat damage, you need something to help go over the top, and you can't realistically expect to get to do that much combat damage with out resistance. On your turn 4 you sunk 4 mana into tutoring basically making mikaeus cost 10 instead of 6.  A real opponent is going to be playing threats of their own, or removing your threats, and sinking 10 mana into a card that is not going to win the game is bad math. As an aggro deck you need to be able to effectively deal with their threats, circumvent them or, remove them.  The bonus to zombies is they're decently resilient to removal.  Tutoring does none of this for you, and it's inconsistent, you're not always going to draw the spell, and if you do always get it then it's a dead card for minimum 4 turns at which you do nothing for a turn while you search your library. On turn 4, jund can be playing a thragtusk , on turn 4 American can be slamming verdict, both of these plays impact the board in a huge way while tutoring does nothing to the board and provides incremental card advantage at a huge cost (sorcery speed too).  Putting consistent and efficient draw card utility in is the best thing for a long game (the long game is not where you want to be, zombies are short game, aggro decks).  Underworld connections, sign in blood, the grandaddy of drawing himself Griselbrand (expensive but effective), these are the cards you need to be looking at to increase your card advantage and be consistent if you really feel like you need it.  Really and truly decks like the one you're attempting to build can get away with a couple sign in blood, but really need to muligan aggressively to get the starting hands you desire. I'd wager you haven't done enough testing with tutor to truly understand how much it can hurt your decks tempo.

You pointed these issues out yourself in your first post, and a lot of these can be solved by simply splashing another color, but I'll try to steer away from that in this post.

1 and 2. You're still building an aggro deck  (zombies are aggro you just have to deal with that)  and you shouldn't be topping out at more than 4 (maybe 5) cmc to be consistent.  Card's like zombie apoc and mikaeus are to expensive and slow to do what you need to do.  Cut the lands to 21-22 and cut these expensive cards.  A couple mutavaults might be good here.

3. Nothing to do about Pillar, it just eats zombies.  Terminus is bad for you too. If you see decks running these you can expect them to side in more graveyard hate, rest in peace kills you too.  Also, scavenging ooze is big and can still eat your undying guys before they return from the yard.  IE: geralf dies, undying trigger goes on the stack, activate scavenging ooze targeting your undying guy in the yard, scavenging goes off first, undying fizzles.  Graveyard decks have really had their time and you might "surprise" some people by running one but don't expect to win 1st place.

4. black has no direct removal for walkers.  the best you can do is something that does direct damage to the player and redirect it to the walker.  Lifebane might help and other evasive creatures, but they are pretty much guaranteed an activation of their walker.  You can try to sideboard some discard cards like appetite for brains or duress. Pithing needle helps against them too.

You need more variety in your creature base.  Blood throne vampire comboes well with the zombies, blood artist, and I would also suggest a set of lifebane zombies. They will be good against decks like naya and jund.  Vampire nighthawks's wouldn't be bad either for now. Butcher ghoul is really aweful, it's a 2 mana 1/1, get rid of this guy.  Get the blood artist and the sac vampire.  You need lifegain,  gift of the orzhov could be money in this deck. Really without adding another color your options become limited.  If you do want to go big black, griselbrand is the father of lifegain and drawing. If you do this you could try the enchant combo (janky, but dangerous).  Speaking of drawing, and card advantage, some sign in blood main deck is what you need, cut the totors, you lose so much tempo and in an aggro deck you might as well be handing them the game if you spend a turn doing nothing.  A 2 mana investment for 2 cards out of your deck is pretty decent. If you think you might be in a long game, you can side something like underworld connections.   You need ways to pump your creatures, Liliana of the dark realms can help you here.  She thins your deck and can provide serious pumpage to your dudes.  The gift of orzhov is great to since it gives evasion.

Either way good luck.