1. I have a 1999 Camry XLE. It has stock components; tweeters are mounted in the corner of the window. Question.. how difficult do you think it would be to remove those and mount new ones? I've never done any audio installs but I will be starting relatively soon. I had lined up - Alpine 9836, Infinity Kappa Perfect 6.1, 2 RE 12" X X X, MTX 1501d modded by Scottie J, and no amp for the speakers.. as of yet (I will be getting one, eventually, as well as some 6x9's most likely.)
2. Do you think it's better with my setup to go with coax or components, as well as ease of install / utilizing the crossover. I do a lot of reading so while I am a novice, I'm a sponge right now and I don't want to invest in noobie gear if I'm going to be unsatisfied in 3 months.
3. Any suggestions on coax or components, around the price range of the Kappas, that may be better?
i'd go the way you seem to be leaning and use high-quality coaxials up front in the stock component locations.
JL audio XRs are excellent coaxials in the $200-$300 range.
if you use a component set, try mounting the tweeters down low with the midwoofers. i use this arrangement in my current system and it works really well.