Can’t answer the first, except that I think you’d need to do a quitclaim deed, and possibly file some tax paperwork. You should probably consult a professional about it. At the very least, a tax accountant experienced in the sort of accounting required when you own an LLP. Possibly a real estate attorney. And of course when the house becomes a rental property, there’s all sort of stuff dealing with depreciation, expenses vs. income, etc.
Second: IRA beneficiary changes are trivial. I could change the beneficiaries on mine in 2 minutes on the Fidelity web page. Depending on who holds yours, you might have to mail in some paperwork. Whatever changes you make, that supersedes all previous designations (e.g. wife + kids on 1/1/2011 takes precedence over wife + father-in-law on 12/31/2010).
Pension plans typically MUST name the spouse as primary beneficiary, unless the spouse consents otherwise. I don’t think the same is true of IRAs but I could be wrong.