I'm not sure how valuable you'll find any advice i give, but frankly im replying as much to help myself, TT can be pretty tricky hand.

Situation 1- I would have to ask if he held kk or aa would he want to risk just winning blinds when he desperately needs a double up? I'd be more convinced he had a premium pair by a mini raise, but its still possible. Against a range of hands from QQ-66 Aks-A10s Ako-A10o you have almost 59% equity vs 41% therefore an easy call. But he is a shortstack and his range could easily be less. If you throw in AA KK your 54%. But honestly there should be some discounting for AA and KK. Since your tournament life isn't on the line. I think its an easy call.

Situation 2- here i think TT isnt strong enuff against 2 hands. Calling is horrible. If your raising it really needs to be a push with these stack sizes. I dont know but theres no shame in sitting this one out and waiting for another spot. If your facing an overpair and over cards your 18%,
underpair and overcards 45% which is pretty good 3 ways, and if both have overcards about 45% as well. The more i think about this the tougher decision this seems to be, i'd love to see what others have to say. Knowing myself i'd probably just push it Pf and cross my fingers there isn't JJ or better out there. I don't think my push would have much fold equity either here to make it 2 way.

PS- I play ridiculously low stakes tourneys and have only been playing a year FWIW.