Time Machine deletes oldest backups?!

Question

So I'm starting to use Time Machine, now that my tape drive went south. I decided to rotate drives and use Time Machine.
I'm reading threads about rotating drives and it seems straight forward. Swap drive, tell Time Machine to use the drive that you swapped in.
Two questions:
1. Does Time Machine know that the 2nd and subsequent backups are incremental?
2. Is there a way to set Time Machine to ask *BEFORE* it starts deleting files?
Time Machine is cool. No doubt. What's not cool is how we have to jump through hoops to get decent backups, with very little "best practice" guidance from Apple.
I want to swap drives and hot have to poke through System Preferences > Time Machine each time I do.
I don't want to worry about being told *AFTER* the fact that Time Machine "deleted files to make space" which is absurd.
System Preferences > Time Machine > Options > [x] Notify after old backups are deleted
It's unacceptable that Time Machine does not warn *BEFORE* deleting oldest backups. That's a decision only the user should make.
Don

Answer 1

don montalvo wrote:
If you swap drives, Time Machine SHOULD be intelligent enough to know where to begin (based on what's on the drive). But it's not.
Yes, it is.  A new drive will, of course, get a new full backup.  Thereafter, if you swap drives, Time Machine will back up the changes made since the last backup to that particular drive, independent of any others.
If you swap, say, once a week, the first backup after the swap will be relatively long, of course, as there's a lot to "catch up."  Time Machine might even have to do a "deep traversal," comparing everything on your system to the backups, which takes a while, too, but it will catch up.
So the issue of data being deleted automatically (where users are only told AFTER data is deleted) is still unresolved.
And it will remain the way it is; Apple clearly changed it because the downside to having backups fail was much larger than the after-the-fact notification.  There were many, many threads in the Leopard forums where folks didn't understand or didn't heed the messages, and ended up with outdated backups when their HDs failed or were hopelessly corrupted. 
And the issue of swapping drives being quite tedious is STILL an issue.
Yes, and there's no indication that will be changed, either.  Apple seems to want to keep things as simple as possible.  There are some workarounds, none entirely successful.  Here's one: http://www.gearz.de/howto/OSX5/changeTMvol-sh-X6
can't wait for Lion to be released so we can see if things got any better.
There's no indication of anything like the things you're looking for in any of the published documents or even the rumor sites.  That's all I can say. 
While Time Machine has some elements of a traditional "Archive" type backup app, it just basically isn't one.  Never has been, never will be.  The main audience is the novice to casual user, or even the power user, who either won't, or doesn't want to, manage backups.  
If you really want an traditional archive type system, get one.  You can't make Time Machine into one.
See Kappy's post on Basic Backup for links to a number of various types.