Portfolio items size and zoom in on hover

Hi!
I want to know how to get some settings on my masonry portfolio:
1) First thing I need is to avoid the items to zoom-in on hover. Maybe it could be done through a code on the change style css as shown on this similar topic I started: https://kriesi.at/support/topic/portfolio-items-darken-on-hover/
2) I have an issue with the items size for 3 reasons:
A) Once I’ve determined the size for every of them, I find them pixelated on high density pixels screens as Macs retinas and stuff.
B) Thinking with logic tells me I have to set item image for a higher resolution to avoid letter A issue but if I do this, items on the portfolio will appear really big (depending on how I change them). The thing is how do I get them sharp and well-defined without compromising the size I want?
C) I am working with a size of 360x169px for the portfolio items under a “Perfect grid” configuration but the problem is that the gallery takes something of the image out. How can I show the exact resolution I want for every picture? I was trying with the different size settings and none of them completely satisfied me so I chose that as the closest.

Thanks in advance!

Cheers!