on the point of lifting or sliding your feet... when I did my 1st dan grading the first bit of feedback I got was I was noisy - sliding my feet all the time. normally I make a point of lifting my feet but failed to do so in the grading. I looked at what I was doing and in hindsight it was very poor. for me, this was a sign that it is something that doesn't come naturally and I need to actively change. it is clear to me that lifting your feet when corner stepping etc is faster, clearer and more effective than sliding all over the place. different mats mean different slide effects so if you slide a lot your technique will change depending on where you practice. lifting your feet is such a basic trait but I see people failing to do it properly all the time. one night visiting another club when I was 3rd Kyu i think. the sensei whispered to the girl I was practicing with and when I corner stepped she stamped on my front foot. it took me 3 times before I realised what I was doing wrong. leaving my front foot out and slowly dragging it back. the sensei told me to spend 10 minutes doing nothing but corner stepping back and lifting my feet so that it was silent. never made that mistake again. great lesson in the basics that stands you in good stead for years. I see 4th dans make this mistake all the time and I always try and stamp on their toes.
Most Aikido dojo do not even allow socks (too slippery). Shoes will damage the mat and also higher risk in injuring your opponent during full speed randori. My foots have been stepped by others and were really painful. I can't imagine having stepped by someone wearing shoes. May be you should try barefoot and if its still too grip, you can put some lotion on an hour before training.