can we have claymore mine back in C3. suggestions ?

For SP yeah I guess. MP - No. Very annoying that you always die from a Claymore without seeing it.

I mostly find the Claymore to be useless and annoying in games...

If you are talking about deploy-able devices (traps). I think it would be acceptable and interesting as long as they are not lethal. Such as a device that could tag hostiles near by, or sap their suit energy. Of course, those devices are also tag-able with the visor, and reward you match score and XP upon destroy.