There have been several articles lately on this subject. What terms are needed in the trust to prevent forced distribution of entire account within 5 years (if this is possible?)

My handy CD Rom program Tax Facts 1 in Question runs on several pages answering your questions. Prop. Regs. §§1.401(a)(9) would seem to warrant paying a good attorney for help rather than rely upon what answers you might get here.
After several reading I quite glad no one has asked me the question you are asking.

CNN's website has an interesting article on using a trust for an IRA.
The URL is http://cnnfn.com/quickenonfn/life/wires/98...0/q_finance_wg/