Vectra C wont start after stalling

[Joshuashaw]

So I recently bought a Vectra C 1.8 02 SXI with 100k on clock with intentions of spending a little on, giving it a bit of TLC to make it into a nice car for getting about it in. I believe I got it for a good price I believe. Body work is remarkable for an 02 vehicle, just minor bits and bats that need a polish. Mechanically it only needs a tinker, few stats here and there and somewhere down the line a timing belt change.

On sunday my dad nipped out in, and brought it home and left it in gear. I always leave my motors in neutral so I guess I have a bad habit of not depressing clutch when starting my vehicles, but dad left it in gear. I tried starting her up and obviously stalled as was in gear and I hadn't put clutch down and ever since she won't start properly. Until the battery ran flat, she was turning over and revs were going up to about 1K then was dying, with engine electronics light coming on the dash - car with spanner through it. I've tried scouring the internet for common problems but not come across anything like mine.

Prior to this problem, the lights dimmed very lightly when full steering lock was applied.

Battery? Starter motor? Alternator? Could throttle body need cleaning? Not had flat spots, not ran in slump mode and did have ample pulling power. Idle control valve? Very small judder on idle.
Could it be a fuse or relay fault? Will a faultcode come up for what has happened? I know I'll have more than one as exhaust gases symbol has been on and off.

Away from this problem, the other minor problems I have are:

Intimittant exhaust gases symbol? Use paperclip trick to diagnose and potentially lambda or other sensors need cleaning/replacing.

Engine temperature never increases, been told by Dad it fluctuated when on motorway but doesn't rise when I've drove in it but not done motorway miles yet. This is possibly why its poorer fuel economy than I planned, Coolant temperature sensors? Lambda sensors, spark plugs, filters and full service will also somewhat improve MPG.

Heater only works on 4 and sometimes gives a real noisy rattle like bearings. Blower motor resistor and heater blower motor from scrappers.

Cruise control doesn't work, not right fussed as I don't enjoy it in my automatic landrover discovery but it'd be nice to get it right. Faulty switch on brake or clutch pedal, and potentially dirty contacts on indicator stalk.

Any help, advice suggestions you guys can offer is v much appreciated. Sorry it's been an essay, but don't want to waste your guys time and ask obvious questions.

[Joshuashaw]

Not going to try and replace anything myself, aside from reading fault codes using paperclip trick. Just want a bit of ammo when I get it to my local garage so I'm not paying them a shedload of labour for them to fault and replace parts ad lib.

[Critch]

Does it crank an not fire now since you've stalled it or just not crank at all?

[Joshuashaw]

Does it crank an not fire now since you've stalled it or just not crank at all?

Not bumped it to charge battery yet, but it'd start and revs would increase as per then get to 1K and die. What are routes to go down either answer to your question?

Many thanks