Apologies for the double post. Though my original attempt did not go through.

BSP is different than npt. There may be an adapter i don't know. You can get that fitting in npt though.

Yes and no seems like quality is a better indicator of how well they mate. I've used dissimilar brands with varying success

Yes they all fit together.

If by type you mean manufacturer then yes. There is supposed to be an industry standard for all cam lock fittings. I have a bunch by at least three different brands and they all fit each other. Cheers!

Yes and no. In my experience they can somewhat fit together but not well. The seal isn't always great because the actual cam mechanism can't fully engage and squeeze the silicone washer if they are different brands.

I've purchased many of the different CamLock fittings from MoreBeer and they fit together perfectly. However I bought some CamLock fittings from another online source and while they did work with these the fit was not quite right. Try to ensure you single-source these fittings.

They *should*. In my experience however interchanging brands lend to difficulty in securing the connections quickly (or in one case at all). Side-by-side I can see a difference in the taper between the two brands I have. Hope that helps!