That sounds correct to me    if you press the pass switch on the left hand handle bar the n/s bulb should flash. There is a conversion you can do on the left bulb to have both headlights on at same time.

As you have split the caliper & pistons are corroded can you not grip them with a pair of water pump pliers or mole grips in the vice & with a left/right movement pull them out,you maybe lucky cleaning the bores & piston seal groove on each side,new pistons & seals lubed with clean brake fluid,once pistons & seals are in lube around them with a smear of red rubber grease.         

Next time it don't start take a plug lead off a plug & make sure you got a spark from the cap.

As darrsi said get one on Ebay for the side you want,the stalks are the same but the lenses are sided as they have the word top on them why i'm not sure.  

darrsi,if the fault is with the starting circuit then this would be redundant when once riding. 

darrsi,just thinking could it be a electrical fault,connection or broken wire somewhere near the front end linked to the starting circuit,ignition switch if it starts after pumping the forks making the loom move connecting & disconnecting,a mare to trace but worth a look me thinks.

ben17484,charge the battery with a charger first, not with the battery charger connected.

Can't help you with the paint code thing but have you tried T-CUT or AG to try & bring the colour back I take it's red which is the culprit,as it's the top clear coat that has faded it maybe worth a try,better with a machine buffer but can be done by hand then a good resin polish.    

 https://www.ajsutton.co.uk/genuineparts/9796/12/yamaha-fzs600-fazer-2002/exhaust?uID=0 

The original front sprocket had a orange centre so it has been changed at some point in the past.

Would normally recommend Motad but someone on here had quality issues & trouble getting them to respond to emails/phone calls & they are a lot more than the ones you have mentioned,but I think I would go for the Delkevic ones as they have the the connecting pipes between 1-2,3-4 as originals it may pay you to get a new exhaust can at the same time if it works out cheaper together it would look better than putting the original one back on if that's what you've got. You will need most lightly to have carbs balanced after fitting the new downpipes.   


Start spraying those exhaust studs now with Plusgas not WD-40 to hopefully avoid snapping studs on removal. 

It's your choice really,shape design, I have a Motad Venom can which isn't loud but louder than standard & with the baffle out burbles nicely when weaving in traffic, most I find only get loud when giving it the beans, even though not the best sound there are a few videos of different exhaust cans,but all the makes you mention are well known, delkevic get a good shout. Had a mate cut down a OEM can a few years ago all the baffles inside fell apart it wasn't great & in the end he bought a new can instead.