1) I had a very slightly different personal statement. I just changed a few words to emphasize IR more specifically in the IR statement, tried to just be a little more broad and all encompassing in the DR one.
2) Apply to DR at ALL the places you apply IR. Nothing worse then getting asked the question... "so, why didn't you apply to our DR program?". Doesn't mean you have to rank the DR program, but DR people have input on your application and you interview with them even as an IR applicant so its best to be as diplomatic as possible. Yes, it makes applying twice as expensive, but you're gonna need DR programs as backup anyway when you make your rank list. If a place has IR and DR w/ ESIR, that's a very good thing for you as an applicant
3) At this time, most PDs are not very militant about prelim surgery. So, for the most part no, but there are a handful of PDs out there who are of the "prelim surgery or bust" mindset. You'll notice the categorical IR residencies all mandate prelim surgery. This is just how the future of IR training is. Best fall in line now
4) Totally program dependent and a matter of personal opinion. IMO, there is no growth without challenge and going through periods of feeling like you have more in front of you than you can handle (both in the OR and on the floor) is how you go from being a med student to doctor. Not to say that a TY won't have moments like this, but you're also gonna have meaningless "research blocks" and outpatient rotations on random things that have no real relevance to your overall career and contribute very minimally to your growth as an IR. It takes more than just 1 or 2 surgery rotations to become competent as an intern on service, it takes usually 3-6 months from what I've been told. You won't get that kind of time to grow as a TY. Also, you may not be treated as an equal on the surgery service...