No, you do not HAVE to do the suspension etc on the Tamiyas, but you can. There are actually two available, one from Wecohe as in the photos of my tanks, and one from Schumo, much less expensive, which simply replaces the stock torsion bars with a more supple one. Wecohe suspension is a bear to adjust, but one you have it properly set, it's grand. These aftermarket suspension systems are for the Tiger 1 and 2, and Panther/Jagdpanther, as they use a prototypical torsion bar suspension.

Stock idler adjustment systems are also good, but the DP spring loaded ones are better, especially if, like in my AO, the soil is full of small rocks, aka track breakers. In some of my tanks I use the DP idler system, in some I use the stock system, and in some I use my own idler adjustment system.

Panther, I never had a problem with the stock tracks, ran them for a while on the Jagdpanther. They are strong and look good. I generally run metal tracks, especially on the competition tanks, for the weight. And never had to buy another metal tub. Don't actually know of anyone who makes one for Tam. As for the fit "issues" with the upper to lower hull, again, not problem, at least for me. The Tamiya Panther was a quicky design and production deal to beat another Panther to market..which they did, anbeit no fault of theirs. All in all, it is a good and enjoyable build, runs quite well OTB, and is hugely popular in EU and USA, and former SSSR.

Expensive as a mail order bride? Son, lemme give you a little wisdom about women: they are without a doubt THE most expensive hobby on the face of the earth, bar none. That being said, they are also the most enjoyable hobby on the face of the earth.