Do those prices included shipping or is shipping an additional cost. I've been quoted both ways before and if shipping is not included the price per pixel was lower for standard 2811 12v pixels. To be honest I did not bulk order last year so not really sure what the bulk pricing is currently at...
It's easy, just warm up the screw cap with a blow dryer or heat gun just enough to make it flexible and pull it off. Just repeat the process to put it on.
Remember the topper! For a Megatree I would push each strand as alternating nodes so I start and stop at the bottom of the string. Then this would allow me to easily put 2 strings per port for only 6 ports and have 2 ports left over for the topper!
Do you want to print thing or have printing things your hobby? There is a difference there.
If you want printing as a hobby then you can follow misterfied's advice and get something cheap and work through all the issues that come with it and learn stuff as you go along.
If you just want to...
Personally, I would stay with well known brands and pay a bit more. Monoprice, Belkin, South wire are all wire brands that I would trust. The search algorithm on Amazon sucks because it gives you what it wants to and not what you are searching for. A few of you search items and then a bunch of...