Brendan,
This is not normal for a 2002, let alone a 1993, immediately I wouldn't try to fix this on your own. My 1999 is not rusted at all. I'm thinking someone missed something on your truck's journey down the assy line (seal coater on drivers side had an itch that needed to be scratched?). Check the passenger side door to see if the same condition exists - not sure if your truck is a quad or not, check all doors. Compile data from other TDR member replies, if someone has a similar issue I'd ask the year and if it too is an 02, if so see if they'll share their vin #with you (if the # is one off from your's it could have been one heck of an itch?). Add this info to what you've found in your other doors and head off to the dealer. Maybe they will rectify this for you. If not, I'd go the next level, I think there's a Regional Customer Satisfaction Rep that tries to handle customer issues that the dealers kick before they make it to DC Corporate. I'm sure someone else will chime in with how to contact them - hope this doesn't reach that level. However, if it does and when you speak to the rep it's worth mentioning that you belong to an organization of 20,000 members that only own our type of truck that is looking forward to hear the outcome of this issue.
You may, or may not, know that Chrysler had a bad rap for being rust buckets - if you've ever heard of "MoPar = Mostly Old Parts and Rust" - that's why. Long before the D entered C, they spent grand amounts of $$$ on R&D and advertisement trying to reverse this rap. Hope you get satisfaction from them.
A thought: It's possible the door to window seal is bad and passing water and/or the drains at the door bottom are clogged - still doesn't sound normal that everything would rust to the point of failure in only 2 - 3 short years.
If you don't wish to go that route and want to just do it yourself, plan on gutting your door (window, tracks, speaker all wiring etc) and spending some time removing all the rust inside, undercoat all metal surfaces (applying pieces of tape to where everything you took out bolts on first and small straws inserted into the drains so as not to seal them) and then removing all rust on the tracks and other parts removed, throughly greasing them (we always used white or yellow grease when doing restorations) and then (since everything is apart) you should probably get new seals, wheels for the window regulator etc. , etc.
With the brief description of what I can only imagine is needed without looking at what's really involved, if it was me I'd try dealing with the dealer as 1st option.
Lastly you could just take some penetrating oil and spray the heck out of everything and get it working again. But I'd save this as the "last" course as it will only prolong the inevitable re-occurrence.
Sorry for the length. Keep us informed.
Joe Mc