Those are just links to manuals that can be ordered. Have you contacted John Deere through their website? Or just called a dealer? Either one should have the information you need and will be able to tell you if a mulch plug was made for that mower and more importantly whether parts and manuals are available. As to whether you can operate it without a plug or chute I would have to assume it works like most other mowers and the answer is yes. Cut grass should exit the hole. Seems obvious but I may be missing something.

Most of the time it is the lower bearing in the lower part of the clutch which is not too bad to replace (about $20) but sometime it is the upper bearing in the clutch which is a little bit more disassembly (another $20 bearing). That is what seems to go out. You can visibly inspect and make sure there is clutch material on it when you take it apart. Do some searching online, you can find it. Don't buy China bearings!

1 Don't sweat it 2 It is easy to pull the rear wheels and gears to clean and lube +plus you can hopefully free the fitting up to get lube in the pivot 3 See #1 The coating you put on , no matter how it was prepped- will be sand blasted off. been there, tried that exact same thing on a new aluminum housing. 4 Just so it firmly engages. Standard cable lube is fine. deere.com may have an owners manual to cover this more precisely. 5 5 gear sets inside selected w/ shift keys. 6 Yes 7 Standard care will allow the engine to last for longer than ever required. Transmissions on these can get water in them for those than blast them w/ a hose to get clean. If the input shaft bearing seems ok, no signs of having been owned by Mr clean and the cable seems to actuate smoothly, the trans should be fine. If you want a yucky job, pull the case sometime and clean it up and re lube. Unfortunately, this year seems to be the demise of these. In my world , I've condemned 3 to death from housings starting to pit through. One wasn't too bad, but needed a clutch- which is not worth it for a machine that is decaying. Enjoy, as they don't make them like they used to.

The boxes are rebuildable. It is hard to believe that is a $750 gear box. Wow. I've only done 2 of these Deere boxes and did gears, bearings, seals etc. If you're concerned about doing the repair yourself, ask the service manager at the Deere dealership about rebuilt cost VS new. You want to know the U-joints are solid yet before they go on to a new/ rebuilt box. The box is easy R&R. If you can do belts, you can R&R the box.