DW and I have been doing a lot of looking and planning and are getting close to purchasing a class A. Can't tell you what will work best for you, but here are some of what we have done.
1) Financing - Shop around. Look at what your bank, local credit unions, Good Sam, etc have to offer in terms of loans. Most banks/credit unions that offer RV loans will post rates/terms on their websites. Experience has taught me not to rely on dealer financing as it is usually not going to be the best finance deal available. Once you decide on what you want to buy and from who, work your financing separate.
2) Not sure the aim of the question. Our concerns were size (we did not want something too big to maneuver) but we also wanted specific amenities in the floor plan. Everybody has different wants/needs, so take time to look at various floor plans and decide what you must have, what you want, and what you are willing to forego.
3) I've learned not to pay a lot of attention to MSRP as each dealer marks MSRP and actual sales price differently. I spent a lot of time on RVtrader.com, shopping various makes/models/floor plans so have a pretty good idea of what is a good price versus what is not so good of a price.
Good luck