First of all, you are talking about three different things:
1)Mutual Funds, which are a VEHICLE for the other two items.
2)IRA (I presume you mean Traditional IRA here, since you talk about minimum required distributions, (MRDs), and there are no MRDs from a ROTH IRA.
3)"401s". To the rest of us, those are 401K plans. They do have MRDs.
"Mutual Funds" don't have MRDs, unless you have them within an IRA or a 401K plan. For example, I happen to have money in several different mutual funds, some of which are in an IRA, and some of which are not.
If you don't know what a SEP or SIMPLE is, you probably don't have one. They are types of IRAs, similar in function to a 401K plan; SEP is for self-employed people, and SIMPLE is also usually used by self-employed or small businesses.
If you have stocks, you have stocks, and you can do whatever you like with them. Cash them in, put them in a safety deposit box (always a good idea), give them away, etc. If they are in your possession, they aren't in either a 401K or an IRA. You can either cash them in, burn them, or leave them for your heirs, and you can do any of these things whenever you like.
I think you would benefit from a sit down with a tax professional who can explain these things to you, face to face. Advice is free. Check your local H&R Block Office. They will probably be open on January 3, and very, very bored, with lots of free time for answering your questions.
Snipes