Yes there are some concerns 1. Engine running lean with the stock ECU and injectors. 2. Detonation/Knock will kill engine very fast. 3. Rod bolts are the weak spot failure after 7800. 4. Did they shave head to raise compression ?
If the car does not want to start the alternator is not at fault unless it was not charging the battery and it ran down. Check the main relay . Was it ever replaced ? When this goes bad it can cause all the problems you explained with the starting In addition let a electrician check all the wire tha...
^ NP however I would not recommend anyone on the last row due to safety . If you get into a rear end collision the people in the last row would get a good lash