Demolish could do with toning down a little but tanks dont do nearly as much tower damage as Aa'ers, Ziggs or others. I think tower damage should vary a bit less, and towers have far too little hp. I shouldnt lose a almost full hp tower because I die or have to back once.
Buffing towers is a nerf to splitpsuhing but riot can still buff them early and I have seen nerfing Baron as a suggestion to buff splitpushing. Splitpushing itself works as is but in yolo queue i think its a gamble on wether your team is going to play aram and lose more than you can gain.