Do I really need a higher powered amp for my rti A1's to play at low volume?

A few years ago, I set up my first 2.1 system for music listening with rti A1's and a PSW 111. I used a $20 amp because it was what I already had and planned to upgrade later. The amp is the Lepai LP-2020A which has only about 13w @ 8ohms per channel. It has been surprisingly satisfactory for my use, which is music listening at low volume. The volume dial is marked 0 to 10, and I usually listen at 2 or 3, never higher than 4, and it barely gets warm to the touch, and to my ear it sounds pretty good. Here are my noob questions:

1) Is it safe to assume that since I never play the volume over 4 out of 10 and it never gets hot that I am not pushing my current amp to the point of clipping? It always sounds great to me, but I don't know $#!% about these things, and I understand that pushing a low-powered amp to distortion will damage your speakers.

2) If I upgrade to a higher quality amplifier, but only use it to play at low volume, do I really need the 20wpc that Polk recommends as a minimum? Why does Polk make this recommendation? I've heard that a higher powered amplifier will "open up" the A1's, but will this happen at low volume? I would like to upgrade but stick to a mini-amp with a tiny footprint, and many of these are low powered.

Thanks!