I don't know if I'm going to be any help here as this has to be a decision that you are comfortable with, but I'll throw in my 2 cents, for whatever it's worth.
2 Surgeries vs. 1 - I don't think you're going to have much choice, that's totally up to the surgeon, either they'll decide where the tumor is located, how much they have to remove and if the tissue is ok and don't have to give you an temporary ileostomy or they won't. I didn't have to have one.
Radiation - I think I tolerated radiation (along with chemo Xeloda only) fairly well during treatment. It sucks, but for me was tolerable. Yes, I have damage from radiation, my gluts are totally shot, but if it's part of what got me here now, I'll take it.
Chemo - there's no way in hell I could have tolerated 12 rounds with Oxi. I was supposed to do 6 rounds of Xelox (similar to Folfox, but without the 5FU pump, Xeloda pills plus the Oxaliplatin). If you do radiation, you don't have to have as much Oxaliplatin as they "count" the prior chemo with radiation. I felt like general shit most of the time. And with Folfox, typically you have to go every other week, vs. the once every 3 weeks on Xelox. Also, if you are only having a few rounds of Xelox, you can forgo the port. Either way, sitting there while they drip poison you is really hard mentally.
I'm no fan of radiation, forced menopause & leather gluts. but I'm also no fan of the neuropothy in my feet that that got worse after chemo ended, the slight chemo brain I have (either not being able to find the right word or mispronoucing a word that I know how to say). Each phase of this crapfest sucks, but looking back, I don't know if I'd want to double my chemo and skip the radiation. It'd have to be some serious proof that this method was better.
Good luck with whatever you decide.