2001 Nissan Maxima GLE Cranks but wont start. Hi all! New here and need some troubleshooting direction.

Hi all! New here and need some troubleshooting direction.
Sorry if this is a long post but hopefully Im providing enough information.
I have a 2001 Nissan Maxima GLE with 160K. I bought it used and it had a pretty rough life. When I first got it it needed a speed sensor (would drop in to neutral randomly), radiator fan assembly, brakes all the way around and a broken lug. I fixed all of that and the car drove great for about 6 months and then needed a new starter. I replaced the starter and battery about 6 months ago and also checked the alternator at the time and it was fine. The car has been fine since except it has developed an oil leak that I have not tracked down yet - needs about 2 quarts a month. And periodically when I start it the Service Engine Soon, TCS Off and SLIP lights stay on and it idles rough when in gear but otherwise drives ok. This will usually happen for a few times and then it will start and run fine for weeks or more. I have not had a chance to troubleshoot that - if anyone has any ideas Id love to hear them!
But that's not what this question is about. Since it is sporadic and wasn't happening at the time of this issue I don't think its related.
Anyway, the car has been running fine lately with the exception of the oil leak. On my way in to work yesterday I drove about 3/4 mile (city traffic) and stopped at a red light. When it turned green I tried to go but the engine stalled - it has never stalled before - and then it would not start. It would barely turn over as if the battery was very low. My 1st thought was that maybe the alternator has gone bad and the battery just didn't have the juice any more to fire the plugs but the Charge Warning light was not on.
A few hours later I went to check on it (my city loves to write parking tickets and boot and tow cars!) and tried to start it while I was there. Now the starter turns the engine fine - a little slow but certainly fast enough and it will spin for minutes at a time so the battery doesn't seem too depleted to crank and fire the plugs. But it still wont fire.
Another piece of information that may be relevant is that the car currently has less than an 1/8 tank of gas and the weather has been very schizophrenic here because of Spring - condensation in the tank maybe?
What are your thoughts on troubleshooting steps from here?
Thanks!