7th

An option to substitute for a G major perhaps?

It may be useful if you're up this way but without the 3 there's no tritone and so the flavour of the chord suffers

In this position the 5 is in the bass

In the 7th position because that's where the first finger is, think of it as based around the F on the 10th fret.

Based on the D barre chord add the 3 note on the 8th fret and it's a D minor chord

The barre chord on the 7th fret is a D and can be used for a major or minor because without the 3rd note it is neither.

The Minor shape with the 5 in the bass and no tonic. In the 7th position it's a Gm chord

No 3 in this one so it's quality is ambiguous but it's a handy moveable shape, based on the open D with the 5 in the bass.

The 5 in the bass works with this voicing too because the 3 and 7 on top define the chord really well. A useful moveable shape.

A useful voicing with the tritone on the top and the 5 in the bass works well in a blues and is a handy moveable shape.