You're basically running into limitations of the generic nature of Maintenance Plans. If they work for you, great. If they don't, the only real recourse you have is to start scripting your own processes. But, you can start with other scripts. The two most frequently used are Ola Hollengren's scripts and Michele Ufford's scripts (just look up the names, you'll find the links). They'll get you going better than using a Maintenance Plan.