Sorry if this is a very easy spot, FLHE is by far my worst game despite being an avid 8-gamer/HORSEster and I generally just try to avoid blowing up majorly minimizing my losses during the FLHE orbits. So anyway this is the FTP 215 HORSE FTOPS a few days back, I play on FTP like 3 times a year so I'd be an unknown, Villain is a random scandi unknown to me. Haven't played any games with him before except for the last 18 hands of FLHE in this tournament. During this time he's opened 2 times and won the blinds (CO and SB), and once flatted SB with about 5 big bets vs LAG BTN and checkfolded 3way on Qxx board. I have opened twice during the same time frame and won both pots pre. So neither of us has played a hand postflop really and thus 0 reads both ways.

We are ITM, 10 ppl left, 9-10 both get $520 and 8th $690, was 8-9k first so no point trying to get payjumps. I'm 8/10 before the hand, almost tied between 8th and 10th, and everyone else has at least double my stack so again I think we need to try to double up instead of nitting in general.

1200/2500 (no antes obv), before the hand V has 17k and I have 18500 (16k+ BB). BTN is very LAG with a big stack, I'm readless on SB but he's a bigstacked Russian also, so I assume he's opening tightish here. Please comment all 3 decisions.

Villain opens CO (5k), BTN and SB folds, I have Jh9d in BB and flat.

Ac9c2d (11250)
Check, he bets 2500, I call?

Turn 7c, we have exactly 10k behind.
Check, he bets 5000, I?

Since he's a total random with no reads this is what I was thinking:

Basically do we want to have a C/R range on this flop? As I said I'm terrible at this game but my thinking was that we don't, because since we have exactly 3 streets of bets left post (12500 on the flop) we don't need to cr flop when we flop huge to get in, and while at first glance it would seem we need to protect vs overs, the only bad cards are KQT and if he hits one of those, wouldn't he check back the turn often to let us see the river? And if checks a KQT ott and river bricks we could just checkfold because it's a pretty unlikely bluff line unless two of the overcards roll? If I cr flop I get value from very few worse hands and no better hand ever folds and it's hard for me to come up with a c/r range. So basically plan was to c-call, checkshove most turns with range, trying to exploit what I assume is a spot people overbluff a bit on the turn in a donkament with these stacks, because it's such a crucial spot for both of us as we both really need to win the pot quite bad and my range looks pretty weak. So if he has Ax+ idk how often I'm getting out of the hand anyway, but this way we'd get to charge bluffbarrels and make good decisions on bad turn cards?

Like I said I'm horrible at this game so idk if that made any sense, but I'd love for someone to correct my thinking here (more interested in thought process than the correct action really). Thanks!