Rated 4 out of 5 stars

As you suggest me, I would like to use ABP just for FR List, keeping using Bluhell. In ABP should I keep EasyPrivacy and MalwareDomains on ? No risk of conflict or slow down using both plugins ?
Other question : On a specific domain (www.leboncoin.fr) Bluhell hides the homepage but not the ads. Seems not to be an EasyList problem.

This review is for a previous version of the add-on (2.0.1-signed). 

EasyPrivacy is also included in Bluhell, even a few hand-crafted domains known for spreading malware are included too, but i didn't put much emphasis on adding more of these since Firefox comes already with good malware lists by default as distributed by Google. There shouldn't be any conflict on using both extensions at the same time, i'm aware of several users using that combo (plus the Element Hidding Helper add-on)

Regarding leboncoin, try cleaning the cache and cookies for that site, since i wasn't able to notice anything strange by visiting it.

Rated 4 out of 5 stars

First day using Bluhell...
Very fast, more than ABP ! Very discret and light
You seem to use Easylist, but why don't add specific country Easylist, like FR or others? Some ads aren't blocked on frenches websites... That's the advantage of ABP, to choose differents lists.
Anyway, thank you.

This review is for a previous version of the add-on (2.0.1-signed). 

Bluhell is designed to be lightweight by blocking .com and .net domains mainly, which are the most used worldwide. Adding the lists for every other per-country TLD would defeat its main goal. There is nothing preventing you from using ABP with just the FR list if you want to, though.