"Would like to know how often MRU-Blaster makes updates available? Noticed that the newest one is 4-12-03."
You can do a check at http://www.dslreports.com/forum/security,1
there is a daily Security Software Updates thread (always the first thread)
"Also, If you delete the scheduler and silent scan, from your computer but keep MRU-Blaster program will it still work?"
Yes, that is how I have MRU-Blaster installed. I like to decide when to scan and and clean.
"If you do delete MRU-Blaster is there any side-effects by just going to add/remove to get rid of it?"
Absolutely Not. MRU-Blaster is a super application.