I think the 85% number comes from this Washington Post poll:
http://www.washingtonpost.com/politics/polling/marylanders-support-several-gun-restrictions-post/2013/02/26/52b32790-8033-11e2-a671-0307392de8de_page.html
If you already own a handgun prior to Oct 1 and you are not purchasing a new handgun, you will not be required to have the "Handgun Qualification License".
If you buy ammo for that handgun (or any handgun), a dealer will not "need" to see the "Handgun Qualification License". It is their store...
A license to purchase a regulated handgun will NOT be required to purchase ammo after Oct 1.
The only thing new related to ammo in SB 281 is this:
A PERSON MAY NOT POSSESS AMMUNITION IF THE PERSON IS
PROHIBITED FROM POSSESSING A REGULATED FIREARM UNDER § 5–133 (B) OR
(C) OF THIS SUBTITLE...
For the OP's original question, you can do 3 lowers at one time on one form.
If you send in your MDC paperwork at the same time, you will have to wait the minimum of either 90 days or when you get your MDC letter (or verify by phone that you've been approved).
This thread has some good general info on the Maryland Handgun Roster Board.
http://www.mdshooters.com/showthread.php?t=117892
This post has a pointer to the April 5 issue of the Maryland Register
http://www.mdshooters.com/showpost.php?p=2337582&postcount=7
Based on those 2 threads and the...