? Using different region save files

[Dr_WPJTPCSPCDM]

This may sound like a stupid question but I'm paranoid so I'm going to ask it anyway. I bought the Mass Effect trilogy on sale from the US PSN store a while back and thoroughly enjoyed it, have been wanting to play the DLC but been put off by how expensive it is. Now I know that DLC is region locked to the copy of the game you bought, but it is currently cheaper to re buy Mass Effect 3 pre-owned and then all the DLC in the current EU sale than it is to buy the remaining DLC from the U.S store BUT can I still use my save files?

 

I suppose there's multiple scenarios here, ideally I'd like to just pick up and go from any save files I have no matter how far through the game I am, although I don't mind having to start Mass Effect 3 again as long as I can still import my ME2 character (also U.S version because trilogy) but I certainly don't want to have to start with a default character with no history. 

 

Also what would happen if I tried using a save file that has DLC missions completed without that DLC being unlocked for the region I'm currently playing. Example I have the digital game + Omega DLC for US, if I put in an EU disc I can't play Omega without rebuying it for EU, but can I use a save file where I've completed Omega and then keep playing through the rest of it and other DLC on my EU version without having an EU copy of Omega installed or will it freak out because I've completed something that it doesn't think exists? No idea if that makes sense, I hope so. Even if I have to rebuy Omega for EU it will still be cheaper buying all DLC + preowned disc than it would be to buy remaining DLC full priced through the US store.

 

Anyway, any thoughts or ideas greatly appreciated. Also please clarify if you know for sure or are just making educated guesses/hunches, I don't mind either response as long as I know that you're guessing.

 

Thanks.

[ihadalifeb4this]

As far as I know you can't use same save file. When I was doing The Shadows Rushed Me trophy for one guy I had to replay everything to unlock HC first cause my version didn't work with his save file.