I not an expert on this, but I think I understand most of these chords. My thought is if you know the definition of the chord, you can figure out what notes are in it, and then figure out how to play it.
If I mess something up here, please correct me (and please accept my apologies).
See if this helps, Tim:
The notes in the major scale of a given key can be numbered (always use Arabic numerals for this, not Roman numerals). For example, in the key of C, it would be as follows: C = 1, D = 2, E = 3, etc. through B = 7, and then on to C = 8, D = 9, E = 10 etc. You've got to know or learn the scales for each key to make sense of the following.
A major chord uses just the name of the key -- example G -- and uses notes 1, 3, & 5. A G chord thus has the notes G, B, & D. If you look at the notes you play to make a G chord, you'll see that each one is a G, a B, or a D note.
A minor chord uses notes 1, 3b (flatted third note of the scale), & 5. Thus while a D chord has the notes D, F#, & A, a Dm chord has the notes D, F, & A. Look at the notes you play to make a D chord compared to the notes you play to make a Dm chord -- the difference is that anywhere F# appears in the D chord, there is instead F in the Dm chord. The other notes of the chords (D & A) remain unchanged.
A seventh chord -- example C7 -- has notes 1, 3, 5, & 7b. So a C7 has C, E, G, & Bb. A Cm7 has C, Eb, G, & Bb. It is understood that the 7 in the chord name refers to what's called the dominant seventh tone, which is the FLATTED seventh note of the scale. If you want the actual (unflatted) seventh note, it is called a major seventh. A Cmaj7 chord has 1, 3, 5, & 7, or C, E, G, & B.
So let's look at these chords.
-G7sus4 -- A suspended 4th chord uses a 4 note instead of a 3 note. So while a G chord would have G, B, & D (1, 3, & 5), a Gsus4 would have G, C, & D (1, 4, & 5). G7sus4 has G, C, D, & F (1, 4, 5, & 7b).
-A5 - B5 - C5 - D5 - E5 - F5 G5 -- These would have notes 1 & 5. Thus A5 would have A & E, C5 would have C & G, etc. Not technically a chord by some (most? all?) definitions, where a chord must have at least three different notes.
-Gsus -- The same thing as Gsus4. The "4" is added to the chord name sometimes to eliminate possible confusion with "sus2," but "sus" is understood to mean a suspended 4th chord.
-Gadd9 -- A G chord (1, 3, & 5) with a 9 added, thus 1, 3, 5, & 9 (G, B, D, A). The reason the added A is called a 9 instead of a 2, which is also A, is that the desired A is meant to be a higher pitch than the other notes (if possible).
-E/B, G#7/B#, F#/C#, D/A, G/D, A/E -- The first letter is the name of the chord, the second letter is the name of the desired bass note. So E/B is an E chord with a B as its lowest note (on the guitar, you would make a normal E chord, but not play the bass E (top, 6th) string, letting the 5th string (the A string fretted to a B note) be the lowest tone in the chord.
-Em7sus4 -- Presumably an Em7 (1, 3b, 5, 7b or E, G, B, D) with a 4 note (A) added. Kind of cheating, as a sus chord is supposed to have a 4 note (or in the case of a sus2 chord --covered below -- a 2 note) INSTEAD of a 3 or 3b note, not in addition to either one.
-GaddE, CaddG -- Here I'm not certain. I don't know if the added note is expected to be on a treble string, bass string, or what.
-C/D, E7/C -- Covered above -- C chord with a D bass note, E7 chord with a C bass note.
-D7sus2 -- A suspended 2nd chord uses a 2 note instead of a 3 note. So while a D7 would have D, F#, A, & C (1, 3, 5, 7b), a D7sus2 would have D, E, A, & C (1, 2, 5, & 7b).
The value in understanding the above is that with that info, you can figure out what notes to play. Sometimes it's pretty easy to figure out how to make the desired chord, sometimes it's a royal pain in the patoot (chord dictionaries can be very helpful).
An example of an easy one is the D7sus2. You start with your normal D7 chord, and see what you have to do to replace every F# note with an E note. In the common D7, the only F# is on the treble E (first, bottom) string. The way to change it to an E is to take your finger off it and play the string open. Piece of cake.
The Gsus ( = Gsus4) is just a little trickier. It's pretty easy to find G, C, & D notes on the first four strings, but tough to also play them on the 5th & 6th strings. The simplest way to make the chord is to use only the bottom four strings.