I have a few rotary buffs. Hitachi which is 1400W and Bosch which is about the same and I have never had a situation where I could put enough pressure on them to slow down at all. Admittedly, 240V, but shouldn't make that much difference..

I just noticed that you're using a polishing pad (Meguires yellow). That won't help you either. Use wool or a hard pad designed for cutting. Then switch to the softer pad for polishing.

As for the lubricant in the compound, that's quite normal these days when we don't use water any more. It extends the working life of the compound and reduces dust. I'd hate to have to go back to the compounds we used years ago. Not that they didn't cut, but they just made a mess.

Also, you shouldn't be applying pressure to the buffer anyway. The weight of the buffer alone should provide sufficient contact with the surface.

I generally start off with a slow speed to get the compound spread over an area on the panel and gradually increase the speed while working. No splatter at all. The variable speed trigger on the rotary buffer helps immensely with this.