If the trans pan is too hot to touch after a mile of driving, there is definitely a problem. I would pull off the transmission cooler return line, point it into a drain pan, have someone start the engine, and see if there is fluid being pumped through the cooler. That transmission is nearly bulletproof, but with serious abuse or a lack of good fluid it can be damaged.

The issue with the gauges is almost certainly a lack of power or ground to the cluster. Studying the wiring diagrams in the factory service manual (FSM) can help you figure out where the gauges get power from and where their ground points are at, so you have an idea about where to start diagnosing.

The sunroof issue is likely the tracks needing to be cleaned and lubed - I have the same problem with mine and haven't found the time to dive into it yet. I'm pretty sure there's a how-to write-up somewhere on this site, some searching should turn it up.

The lack of acceleration could be from the timing belt having jumped a tooth. Do you know how long it's been since the timing belt was replaced? If not, it's something that you should be planning on doing in the near future. You'll want to replace the water pump, timing belt pulleys and tensioner, and crankshaft front seal at the same time. Replacing the other engine belts makes sense if they're showing any signs of aging. You'll also want to check to see if your engine has the most recent updated crankshaft bolt and install the updated part if it hasn't already been done.