Or perhaps three problems:

Typical symptoms of a slipping torque converter. Check your trans fluid for level and color.

I checked it a few days ago and all was ok. AFAIK trans fluid was changed about 15k miles ago by the previous owner, so it shouldn't cause problems. Unfortunately I wasn't able to do anything over the weekend, but today I want to look at the brakes or take my bonnie to a mechanic to check for the electrical stuff.
The problem is - all those things happen at once (if they do). Yesterday I made a trip of about 35 miles and experienced no problem, except that TC remained constantly off and I was unable to switch it on. Today, while I was driving thru the city (ca. 4 miles, not a big distance) sometimes all was right (with TC off) and sometimes all sucked:/.

If most of those problems are mechanically unrelated to each other (e.g. ABS/TC and CC, I don't know about the torque converter and ABS/TC) I suppose the source should be of an electrical nature.

One more thing - these problems (ABS light on, TC "stuck", no CC) often start - when they do - when I start the engine and before I even move the car or use brakes. Doesn't this look like an electrical problem?
Anyway - I'll take the car to a mechanic - hope he'll be able to solve the problem

Sounds very electrical or the system sensing a fault if it does a test at startup. I'm not faililar with the tests run at startup though.

Well I couldn't find anything so it found me . "Luckily" (for this case only) I happened to forget my radio panel in my friend'* car and had no music for a few days . But no problems with TC/ABS/CC as well. I'll have my radio back today and I'ii see what happens. Think I'll have to deal with all this Total Cable Disorder :? behind CC/radio (I have my 1-DIN-sized radio mounted below the stock one). Though I'll have to hold for a while because with -12 F outside I am not that willing to do it this week

If you think you have a hanging brake, just use my test or driving along gently when it'* doing it to cool brakes, and on an uphill grade coast to a stop without using service brakes or emergency brakes. Use you fingers -CAREFULLY- to check temperature. Don't touch without holding fingers close to sense heat radiating off the rotor or drum first...!!!

I've identified a brake not releasing all the way by that method. It would causes front wheel to act like tire was out of balance at times and not at others. Pins were dry and caliper wouldn't slide easily. I replace calipers with remanufactured. Cheap and easy. New pins are nice if they're corroded any. Then you're done with brakes for 80K miles again. That'* even with another pad change.

PLEASE: DO NOT TOUCH ANY PART OF THE BRAKES if you have used them. Temperatures can be extremely hot. That heat gets conducted by the rims and even the rims can burn you if the caliper is hanging enough.

don't worry . My brakes do not get hot at all, they happen to be warm at best, which is normal. Meanwhile, I got my radio finally back and there'* no problem with the electrics anymore (so far). I'll leave it as it is and will thoroughly check my electrics in a few weeks/months. Anyway, it'* too cold around here to do anything outside :? . Thanks for all the support.

It probably dried out and life is again good...glad to hear it.