Some questions about images

[Frythle]

Hello all. I am a new user of Prestashop and currently trying out version 1.7.2.4. 
I have some questions regarding image sizes tho. I am aware that PS automatically does the optimization of images for each field, but I am a little worried about this option. Is there a way to turn it off?? What I am worried about is that I will have around 8k -12k products on my shop and with all these automatically generated images, I am scared the site will get HUGE.

Also, is there an option to turn off ALL prices on articles? or do I have to change it one by one?
Another question I have is about product combinations. If I turn it on for one product with, let's say, 12 colors. Does this generate 12 different pages? or how does it work?? 

I think that's it for now. I do have a million questions but these are the ones that worry me the most.

Thank youu for your time and hope you enlighten me with your brilliant answers.

[NemoPS]

For image sizes, you can really just erase them if you don't want them to be used (make sure there is no reference in the template though)
For prices, you can turn them off for each customer group in the groups area
Combos do not generate extra pages or products, it's all managed with javascript on the same page

Good luck!