well done, always nice to get a good payday. i actually like being a big stack, i know you have finished now, but my advice for the future would be- if the table is weak and tight, then play very loose and steal lots of blinds. fold to any 3 bets unless you have a good hand to avoid getting into tricky spots, then just steal again the next hand- especially from mid to late position. sometimes i end up playing like a mad man, i hadn't played in like a week so i decided to play some $0.25 sng mtt's, 90 man ones. on the final table i got the chip lead and when we were 3 handed i raises like 85% of hands because the other players kept folding, and any time they re-raised i simply folded. i won 2 of these in a row so was nice to get back to winning ways.
then yesterday i went into a $7 45 man sng mtt in around 3rd place, because i was in a decent spot, but not chip leader, i simply raised my mid to strong hands, as opposed to junk hands. such as raising with Q 10s etc. when we got to 3 handed i noticed that these weren't amazing players, so i played controlled aggression, shoving Kx sb v bb and folding a lot of buttons unless i had Ax a pair or decent broadways. i ended up winning.
on the other hand if the table is very loose and 3 betting, shoving Q Jo etc. then i would use my big stack to simply look by and wait for strong hands A Q+ and 8's or 9's+ and just let the others ko each other. pick your spots to steal in this case, perhaps shoving from the button with Ax v shorter stacks in the blinds etc.
so basically, alter your strategy to see what you see suitable for the table and the standard of players. well done on your 2nd place.