Advice for post rotation Sligh

First off, until we have spoilers for Khans (more than 3 cards at least) it really is trivial to stress about making a deck "rotation safe."  I'm sure you're tired of hearing that by now, but the simple fact is that 1/2 of all the cards available to us are rotating out and we have no idea what 246 of the 269 incoming cards are (note that 3 are spoiled and 20 are basics).  The best plan you can make would be to look at Theros block constructed builds and draw inspiration from those.  Identify the cards rotating out and see if there are comparable replacements that WON'T be rotating.  If so, you're in the clear.  If not, well, the strategy might not be viable post-rotation.

That being said, you want to go red aggro (aka Boss Sligh), there will be a ton of options available I'm sure.   The build you currently have actually doesn't look half bad, but could probably tinker with the burn options to make it a bit more pressuring.

For the marauder, it's definitely worth a go.  I'd suggest tossing in something like Hammer of Purphoros to give everything haste (likely in the SB) to make them more effective.

As for Stoke the Flames, the card is the real deal.  It lets you take your 4 tokens that would achieve nothing and just tap them to do major damage.  Think, Elspeth is on the field, you can't get past her tokens, but you certainly can  blast her in the face.

I'd also keep a keen eye on whether there is a 4 CMC sweeper or not forthcoming as an article I read yesterday seemed to suggest that there might not be one at 4, rather, relegating that to the 5 CMC (which certainly would make aggro happy).

Lastly, I'd be curious to see your sideboard.  How would you deal with other aggro decks?  How about Mono-green Devotion (who will dump out a similar number of creatures that are, on average, bigger and more threatening)?  How do you respond to decks running Anger or Drown in Sorrow?