System Placement Question

How about switching to a big pair of Class-A monoblock amplifiers -- Krells come to mind -- and then turning off the radiator, leaving the amps to heat your place?
Just a thought.

If your amp and CDP are kept to the side and your speakers can be pulled away from the wall and spread far apart from the radiator you have no problem. If OTOH the speakers still will actually get hot from the radiator then...You are stuck using the long wall. Just research the numerous threads, white papers, ratios, triangles, various ancient texts, and religious belief systems, damping materials, baffles, busters, deflectors, absorber, to get inspiration for the reiterative process of moving your speakers around until they sound best from the listening position while decorating your apt at the same time. I never did get my wife to like the hanging sheets of Dynamat, no matter what color they were.

How wide is the room and how long is the radiator? Would you be willing to purchase longer speaker cables to put the rack and TT on the side wall?

Components are made to run warm to hot , i would not worry about them . Speakers are different thing , If the rad is making them hot to the touch , you may be able to build a deflecter , so the heat from the rad radiates away from your stuff .