A towel for your headset and top tube, a headband, and industrial sized fan will do a lot to prevent sweat dripping on your frame. Aluminum will still corrode from sweat from normal use and your bitter tears during an FTP test.

I like direct drive trainers as they are so much quieter than wheel-on ones, you really only get drivetrain noise. Lots of new ones seem to be coming to the market so there are lots of choices. The recent JetBlack Volt looks intriguing to me, so might be one to check out.