I'm very new to playing Omaha and a few questions came to mind with starting hands...

- Why would a hand like J,10,9,8 be better than Q,J,6,5? Is the former not blocking some of its own outs?

- Is a hand like J,10,6,5...two separate connectors, even considered a playable hand?

- Are there any connectors that are simply considered too low to play?

- Am I correct that in a rundown, a gap at the top of the rundown makes a hand unplayable? Why?

I hear of the importance of always drawing to the nuts, though I also here of the importance of suitedness. Isn't there a conflict here? How important is suitedness really unless it's a suited A?

- What's the lowest pair that is considered playable whether as part of a 2-pair hand or a pair and connectors? Is a single pair, even AA, even considered playable if the hand doesn't have anything else going for it?

Thanks!

Don't use the word 'playable' or 'unplayable' like that. The situation has a big effect on which hands you should play -- opening UTG is many times tighter than defending your BB against a SB open, for example. Only a small % of hands are objectively unplayable as in you wouldn't enter the pot in the scenario that calls for the widest ranges.

The double-suited JT65s are okay hands, even rainbow JT65 is bad but still can be VPIP'd in certain wide range spots. 5432r utterly blows. Borderline unplayable.

Gaps at the top making rundowns unplayable? QT98ds is still a great hand. All else being equal, gaps at the top are slightly worse than gaps at the bottom. That's the sober way to put it.

Some of the ultra-low rainbow single pairs are just about bad enough to be considered unplayable. K722r, lol. 22xx-55xx with literally nothing else kind of suck. It's situational whether AA72r is a good hand or a pretty good hand; would never describe it as 'unplayable'.

Other questions: JT98 is way better than QJ65 because it flops straights more often, straight draws more often, and the straight draws it does flop are better on average. That's really important stuff. Blocking own 'outs'? Well you have a lot more to begin with, so to speak!

Low suits are better than nothing. Low suits are less important than high suits -- AdTd3h2h is better than AdTd3h2c by a smaller margin than Ad3dTh2h is better than Ad3dTh2c. But even the lowest flush is still a flush where you'd otherwise have nothing, winning a higher % of pots and thus getting more EV (as long as you don't play badly lol). The importance of non-nut suits is proportional to the width of ranges. Q-high suits are pretty good heads up against a wide range, for example, and their value drops in multiway pots and where tight ranges.

JT98 will also flop 2p+straight draw while QJ65 cannot.

pure run downs with no gaps will give you much stronger flops vs QJ65 that will give you a ton of speculative flops where we aren't that happy , typically a hand like QJ65 will have to be double suited and opened from later positions if we are going to play it

The biggest problem holdem players have when thinking about starting hands in omaha is they think having four cards equates to having two holdem hands. It doesn't. It equates to six hands.

JT98 combos:
JT
J9
J8
T9
T8
98

compare that to JT65

JT
J6
J5
T6
T5
65

One of these lists is a bit better...

When you add in that you have to use both cards of each combo, the J5/J6/T6/T5 combos are even worse as omaha hands than holdem.

They aren't unplayable, the usual problem is you'll have higher two pairs and better straight draws with the gap at the bottom on the flop and better hands on the river ... hand vs. hand the gap at the top will be much worse on the flops they both hit a straight.

J987 vs. JT97 on ...

865
J987 = nuts and some backdoor equity
JT97 = nuts and a 9 card redraw

T87
J987 = nuts and bottom two
JT97 = nuts and top and bottom

T98
J987 = 2nd nuts and bottom two
JT97 = 2nd nuts and top two