I haven't looked at that warranty in detail, but generally speaking this should help.
What is GAP insurance?
In the case of a total loss/write off gap insurance covers the outstanding finance after your regular insurance pay out. The two won't match up usually because of the depreciation right after you buy the car. For example, if you take out $20,000 finance and buy a car, then write it off after six months, your insurance company may only value it at $16,000 but it's unlikely you will have cleared $4,000 from your finance. Gap insurance will pay out the difference and settle the debt.
Will Chrysler change the engine, if it comes to bhore?
Yes, unless they identify misuse or deliberate damage. For instance, if you do 1000 miles and the engine explodes, it's a mechanical fault that the warranty would cover. If they open up the engine/look at diagnostics and find it's been thrashed to within an inch of it's life, they may claim it was your driving which has destroyed the engine and you would have to prove it was an underlying fault and would have blown either way.
Will car dents be covered with this bumper to bumper insurance?
Not likely, as I mentioned in the last point, if it's your fault it wouldn't be covered. I think you may be confusing the terms insurance and warranty at this point. Insurance would cover your dents but a warranty only covers the manufacturer's faults, even in the case of extended warranties.
What does basic mean in terms of warranty?
Sounds obvious, but whatever Chrysler want it to mean! There's no legal definition of 'basic' so you would need to check the documents thoroughly or ask them to explain exactly what is and isn't covered. If they're reluctant, it's probably because 'basic' covers very little...