Filter size and application (newbie alert)

[SteveT]

So my imaging setup consists of Equinox 80ED APO with a 350D (self modded) connected to the focusser with a Cano T Ring, a 2" FLO T mount and a WO 2" focus extender tube (from FLO). I have used it once and achived focus and can take images so thats all good.

Now, I am considering some filters,am I correct in thinking that as the 2" T mount is threaded for 2" filters that considering my path from the focusser to the camera is all 2" that i if i put a filter in the path, i should put a 2" one in the threaded part of the T mount ?

It seems obvious I know but i ordered a 1.25" filter on the assumption that i would stick it in the eyepiece before i remembered i dont use the EP for imaging .

When it comes to visual use, would i use a 1.25" filter in the eyepiece (Cel X-Cel LX) or use a 2" filter (same one as imaging) in the threaded section of the diagonal which is a WO 2" dielectric diagonal (with SCT adaptor)? The diagonal has a 1.25" adaptorin for the 1.25" eyepiece.

What i dont want to do is buy 2 filters of the same type (where appropriate) when 1 size will do for both.

Also, I have a C9.25 OTA coming sometime later this month hence the SCT adaptor.

I assume a 2" filter is much more optically preferable in the imaging light path than a 1.25 one? In fact there is nowhere to use a smaller oneother than the eyepiece.

Also, can use use multiple filters in the path (i havent checked whether this would be possible but the threaded tubes seem deep to allow this?

Thanks for any advice.