Products photos urls

[Jurist]

Hello everyone,

I have a problem with prestashop 1.5 (atm moving to 1.6) and ebay module 1.6.7. I list my products on ebay through prestashop back office with help of this module and everything is fine except one thing.

After some time photos disappear. Instead of them there's a question mark saying that image is missing.
I think prestashop moves them. Could this be disabled?

Next thing is products URL. I know prestashop puts images in folder yourdomain/img/p/5/3/28_home.jpg (example) which is very unclear for me and I'd like to know if it is possible to put ALL images in ONE FOLDER? Images should be ID titled but what if one ID has many photos... Which file should I edit and how?

I would be grateful if anyone could be so kind to help me.

regards.