you asked "
Are there certain components that could be so bad that it wouldnt be possible
to get the allignment done without their replacement?"

The answer is Absolutely.... but you can't always trust the alingnment place to tell you that... many will go ahead and " align " it knowing it is meaningless without the new parts...I used to work as both mechanic and front desk for a front end shop.... but I don't know enough about MB specifically to say which items... but when you get them fixed you should do as complete a replacement as you are able ,, because leaving worn components in the system causes the new ones to wear out much faster than they would otherwise....