There are currently no restrictions in the rules as to how many times you can transfer points out of or into your MVC account.  Its one of the huge benefits of the program.  Certainly allows for flexibility on either end if you find your self with too many points in a Use Year….or too few.

I am thinking about joining have my return presentation in about 40 days.

There have been some new status tiers drafted for the MVC points program, that they are currently rolling out during presentations that are likely different than you encountered during your first pitch.  If you want a head start of knowledge going into your return presentation, check out this ongoing thread over on TUG.  http://www.tugbbs.com/forums/showthread.php?t=222893  There is an attachment in post 1 that lays everything out. 

I'm certainly not the most experienced person that can reply, but I think the sales people typically play down the transferring or “renting” points options.  After all, they want to sell you as many points as they possibly can.  Different DC members have different ideas as to the minimum number of points required.  As for me, I'd buy something like 1,500 or 2,000 and then rent the rest.  You can always buy more and add them on later.