Farmer...welcome to the forum
. You have certainly picked the right place to get help, suggestions and support for your new to you Winnebago. There are some 32T owners here who will likely respond soon.
My thoughts on PDI in general:
1. Take a flashlight and creeper (or ask the dealer to provide a creeper). Don't be afraid to roll around under the rig and inspect things carefully...look for telltale leaks, stains, rust, etc.
2. Tires on a 2001, if original, need to be replaced. If you haven't worked that into the deal, try to do so before giving them any $$$.
3. Make sure everything works...slides, leveling jacks, water pump, water heater, fridge, TV's, lights, awings, etc. When we bought our rig used, we stayed in the rig overnite on his lot before leaving...had them fix a couple of things we found by virtue of using everything.
4. Check the roof...make sure there are no issues with caulking around vents, skylight, antenna..etc. Check the roof/sidewall edge and make sure it is caulked well by pressing on the roof radias just above the seam. If the seam opens up anywhere, make them recaulk.
5. If this is your first diesel and you have not already done so, consider letting a qualified diesel mechanic check over the engine, drive line and chassis in general. Depending on how well the coach has been serviced (insist on seeing prior service records), you may need coolant flush/fill, new hoses/belts, new air, fuel, oil filters, air dryer service. Diesels are great but can be very expensive to repair so make sure it is in good mechanical condition and all service is up to date.
I am sure others will respond with things I've forgotten. Good luck and come back often to share your RV experiences with us.