1. Its easy to get the headlight bulbs in upside down -maybe thats whats happened here. Easy to check, just take the bulb out and make sure the filament is hanging down rather that up if you get what i mean!
2. Why would someone do this? Get some from a breakers and put the twin ones back on. However depending on the type of wipers fitted it can be difficult to get the spray to hit the screen and not the wiper.
3. Think you mean emissions are high. Yep,get i diag check done,preferably by an Alfa Specialist.
How much fuel did green flag put in? In my experience people who do not understand Alfas think that any non starting problem is either the cam belt or the fuel pump. Again, you'd be best off getting the error codes read.
If you have a lap top and a few quid you can buy the software and lead and read the codes yourself, might be easier than trying to get a non runner to a garage.