Research is a big plus if it means you've made contacts that can write you stellar LORs. If you want to stay in house and have impressed the big wigs at your school, this should help considerably. Showing dedication to the field will also set you apart, seeing as most people become interested in radiology later on in the process.
Straight passes in third year is a moderate-strong negative. Many of the better programs want candidates who have multiple honors in third year. Do you have opportunities left to get honors in courses? If so, work as hard as you can.
Issues of third year grades are always tricky - some schools give only the top 10-15% honors (as in my school) and the rest passes, with no in between (luckily, my school has an H/HP/P/F system for third year, and that intermediate HP does help out a lot). I would like to say that committee members take this into account, but I have the suspicion that many don't as much as they should. Try to do your best in your remaining clerkships.
Your Step I score passes the threshold, but isn't going to turn any heads. Consider taking Step II early and demonstrating a significant improvement, especially considering your third year grades.
All in all, you should have no problem matching somewhere, but depending on the quality of your program, being where you want to be may be considerably more difficult.
G'luck