I play a lot of live MTT locally

During the open blind levels I play super well, I build a decent stack with a little aggression and some solid reads.

During the middle of the tourney im usually looking at 80 BBs

Then things go south I usually dwindle down.

I've tried continuing aggression through the middle stages of the tourney and it usually doesn't end well. I try to tighten up and end up blinding out before the bubble. I feel that grinding out premium hands wouldn't be smart because you still want some wiggle room when the blinds start getting high.

I play the final table great when I make it there i do well, at least in my eyes. I do not have any solid evidence here. Im more looking for advice for mid level play?

Also side question im a younger player, the older players seems to always call me off because of my appearance i guess they assume im always bluffing, which is great because ill always get payed. When i find myself in that situation, I should just accept the free money and not get out of line right?