My stepdad is a mechanic and has a TON of experience (even had his own shop) and said it is fine and to leave it alone. His friend owns a Kia dealer and can get the parts to me for a big discount
I know exactly how you are feeling. I am an experienced wrencher (personal, not trade) and can assess damage and feel confident in what needs to be done. My GF's son, however, is not mechanical at all, and the C4 he's driving is a solid car, but has a couple of issues now and then that have him thinking it's a dud. I'd buy it from him and drive it in a heartbeat, except it's not a very desirable - or fast - car.
The bumper cover can be easily repaired, it's not hard to patch "plastic" and, as it will be painted, it's also easy to blend the repair into the original material. I'm not an expert, but I've made repairs vanish to where you'd have to look closely to tell - there are plenty of youtube videos out there. A pro could respray a removed, repaired and then prepped part like that for very little $$. A friend of mine will do it for friends and family for cost of materials - he enjoys helping people out.
In your situation, I would trust your stepdad's advice. You'll pay a lot less than the $1000 deductible.
Intercooler needs replacing . As soon as you damage the cooling fins its stuffed.
Not true at all. Nothing flows thru the inside of those fins, they simply dissipate heat conducted from the (in this case) horizontal passages as air flows between them. Even if one of the passages was cracked, it would be simple to seal up, it's not under (much) pressure, and airflow isn't an issue because it is being forced by the turbo. Fins can be straightened, they sell simple tools (like combs) to slot in. Do it all the time with traditional radiators with stone damage, oil/transmission coolers on cars & trucks, etc.