Well, CEA mirrors the NTSC version of H1, whereas I use the PAL version of H1 (here in the UK). There are some things you can do in PAL which you can't do in NTSC, and therefore can't do in CEA either. However, aside from certain bridge descent methods in AOTCR (details in my bridge descent guide), that's not much. So, you should be able to do almost everything. Any time something is PAL-only, the relevant article at my site will helpfully say so, I hope.

Mind you, one difference with NTSC and therefore also CEA, is that enemies move faster (as do you), and rates of fire are I think generally higher. That could make certain combat challenges significantly tougher. For example, in BCM3 I manage the Flood onslaught challenge on Legendary, but I remember it feeling a lot harder when I later tried it in CEA (I can't remember if I managed it). So, better keep that in mind.