This thread got me curious about mine. Once I finally ID'd the correct key for the pin and WD-40'd the lock, the hitch itself pulled right out. Texas is good for something, I guess.
Had same problem on old jeep grand cherokee. Hooked a semi tow chain around a large tree and floored it and fucker stopped me dead in my tracks twice. Try shooting aero Kroll in there every night for a week or two then tugging on something firm. Never did get mine out but on old shit at work I'll hit it with Kroll every day for a week and that stuff works pretty well.
If you have welding skills and spare time you can weld a nut on each side of towbar then a plate to push off of on the hitch. Tighten it some each day and spray with aero kroil
I've been driving it the past two days to move my shop...somehow I'm not worried about scratching the paint
Nah Salt and moisture over time will stick aluminum just as bad. Ok maybe not as bad but working around boats and salt water I can tell you your still in for some hard work given the same issues OPs shit was treated to.