You would hold Planar Cleansing in your hand until you need a wipe, not cast it and let it sit there (that would be a terrible card). Cast it when you need it like any other wipe, except it goes off on your next upkeep, and hopefully no one disenchants it before then, but it's a cheap 2 cost wipe (in theory).

Topplegeist could be better than Ghost-Lit Redeemer because Topplegeist flies and has the potential to tap something every round in addition to tapping when it enters the battlefield (ETB), but if you think the life gain is more important, than keep it. Often times life gain in small amounts is just a stall tactic that doesn't give you a stronger board presence, up to you though, I feel like you like life gain more than I do, and if you don't like tapping mechanics, then leave Redeemer in.

If you have no good targets for Guardian of Solitude, it's basically a 1/2 vanilla creature for 2 mana, which sucks. With consistenly good targets, it's ok. When you consider there is a good chance that Traft will be on the battlefied at the same time as Guardian, it could be pretty strong since you could make Traft fly over an ground creature that would destory it if blocked.

I'm not a fan of Keening Apparition. Without targets it's a 2/2 for 2, which is better in limited when dueling. With a target, it's ok.

Guiding Spirit and Latch Seeker are just ok.

Tallowisp would be good now that you have a couple "enchant creature" cards, but you only have two, so Tallowisp's usefullness might not be great, especially if you already have one of your enchant creature cards in your hand or on the battlefield. 1W 1/3 Whenever you cast a Spirit or Arcane spell, you may search your library for an Aura card with enchant creature, reveal it, and put it into your hand. If you do, shuffle your library.

These are all just my opinions. Every card you use will be relevant at one time or another, it just may fluctuate in frequency. I feel like one difference in our play style is that you will more often than myself put in situational cards, because you like it when they become relevant. For me, I want more consistency and reliability. Build the deck the way it will be fun for you :)