about the pixelated view: check your preview panel settings. there is no RAM preview anymore, in the sense that there is no special designated keyboard shortcut to do that. you can set to preview your composition in any of the shortcuts with much flexibility. check your preview panel. this how I set mine for Numpad 0 - this how old RAM preview (prior to CC2015) worked
notice the resolution popup - when it's set to auto, it takes the information from the resolution popup of your composition. probably what you want.
if you have made a mess (it's easier to mess the preview panel than ever before) just click the reset button
I didn't only mean the RAM preview. It's also when I look at every single frame, it's either pixelated or completely grayed out with the background.
check your fast preview options
if adaptive resolution degrades your image too much, you can set it's preferences in the renderer options. in some cases you would want to set it to Off (final quality).
see if that works for you.
I would also try to purge the memory: edit->purge->all and see if the new preview image looks better.
Perfect! I've been struggeling with this for weeks! And Adobe's chat support wasn't able to help me and blamed my GPU. Thank you!
Great. guess it's the luck of the draw sometimes with support. I think they are much more helpful in installation problems than in interface or under the hood concepts in After effects.