Hello,
Here are the answers to your questions:
Once installed, and a new version is released, do I then have to re-code all existing pages?
No. Once you set up snippetmaster, no additional changes are needed for your webpages, even if a new version is released.
Is it possible for end-user clients to up-load flash, video, you-tube, gif89/or animated gifs, and mp3 files yet?
Yes. You can specify upload groups, which allow users to upload any files to whatever location(s) you specify. Each user can be assigned to any Upload Group, so you can control what locations your users are allowed to upload to, etc..
What file types are not allowed?
You have full control over what file types you want to be allowed or not allowed.
Can end-user content be associated with form-fields via SM?
I'm not sure what you mean with this question. Your end-users can edit any content you wish them to be allowed to edit, using the WYSIWYG editor, or if you prefer.. you can disable the wysiwyg editor and limit them only to a standard textbox. You can do this on a per-snippet basis... or you can make this an entire "site-wide" setting.
Are there any known problems associating SM with data-bases?
No. No problems.
During install I see that SM can be installed into a chosen sub-directory of the main root which in-turn affects subsequent sub-directories and their associated files (linear); question, can this sub-directory be in a different tree under the main root while still accessing other trees and their subsequent sub-directories (non-linear) ?
I'm not sure I understand this question.
If you install Snippetmaster into a folder like this:
http://domain.com/snippetmaster
Then you can still use it to edit any files in http://domain.com without any problem.. or any folder in the website with no problem.
Each user is assigned a "starting folder" and "starting URL", where you want them to be located when they login.
the location of the snippetmaster program files has nothing to do with the files you want your users to be able to edit.
Cheers!