yes u r rite, rust is a gift og karachi. now ur car is newly painted, get it treated from the painters.
as for wiring, please sort it on priority becuase one short circuit and its all gone. belive me these mechanics and dentar/painter when the take out things and fit back, they dont do it properly and just KAAM chalatey hain.
Once i remember i took my car from dentar when he applied dammar beneath, i was on hyderi road and the left wheel of my car came off and went pass by me and by god it didnt hit any car. i called dentar he said he forgot to tight the nuts.
So get underneath and check the wiring by ur self, loose ends, joints etc.
as for headlights, buy phillips Rally vision 100/90 watts bulbs. they will cost around 850-900 a pair they are perfect and much better that osram and other local china / taiwan ones. there is one more rally vision comes which is around 4000-5000 as pair. but i think the cheaper one does a good job.
the chewing gum can be taken off using wd40. tere are many videos on u tube for the removal do check them.