1. Laser or Optical is best answered by asking you what you do or play most.
If you told me you mainly FPS, I'd say optical. If you told me your a serious MMO player, then I'd say laser. If you told me it's a mix of both I'd say choose. If you told me you need a steady slow precise mouse for artwork I'd say optical. If you told me you rarely play games or don't put much weight into them I'd say choose.
Which ever you decide, most importantly
will be by finding a mouse that fits your hand best. Offers side buttons you need or the extra buttons you don't want that might get in the way. Sometimes no matter how hard you want either laser or optical if you can't find a comfortable mouse it's going to be the wrong choice anyway.
Depends who you ask. In this section of OCN seems most users prefer optical by choice but not because it may be better for what they are being used for.
2. Lasers track better on hard pads like aluminum's & plastics. Optical sensors do better on soft pads like cloths & hybrid materials. I prefer my pads center area where I do the most mouse tracking to be solid colors. Some patterns can mess with some mice sensors.
Have three computers between home and work not including the wife's laptop. Pads I currently own and have tried both laser and optical mice: Razer Vespula
, Steel Series Qck
, Steel Series 4HD
, Mionix Sargas 320
, Mionix Ensis 320
, Roccat Sota
& have an incoming Roccat Taito
today. (Love trying new gear....computer hobby).
An example I had with my newest optical (Roccat Savu) was on the Sota pad, which is a flexible plastic surface, the sensor felt a bit too 'speedy'. Same settings on a cloth pad and it was just fine. However, I fine tuned the mouse settings by turning down sensitivity slowing the cursor on the Sota and it's fine now. Though I can make it work I'd rather place it on cloth where I don't have to adjust sensitivity and obtain most accuracy. So keep in mind to some degree adjustments to mice settings can be made to accommodate your pad possibly.
Happy mouse hunting.