After the Gloria, catch a quick breath; the Liturgy of the Word awaits. You did know that the readings may be sung, right?
4. When there are two readings before the Gospel, the first reading, which is usually taken from the Old Testament, is presented according to the tone for readings from the Prophets, and is ended with the customary form for a period. The conclusion Verbum Domini is also sung with the same form for a period. Then all respond Deo gratias, in the customary way at the end of readings.
5. After the first reading, the Gradual Responsory is sung by the cantors or by the choir. The verse is presented by the cantors up to the end. Hence there is no reason to have the asterisk, by which is indicated the resumption of the chant, to be made by the choir in the end of the Gradual verse, the Alleluia verse, and the last verse of the Tract. However, when it is seen as suitable, it is permitted to repeat the first part of the Responsory up to the verse.
In Paschaltide, the Gradual Responsory being omitted, Alleluia is sung, as described below.
6. The second reading, which is taken from the New Testament, is sung on the Epistle tone, with its proper final cadence. It can also be sung on the tone of the first reading. The conclusion Verbum Domini is sung according to the second melody notated in the common tones, and then all respond Deo gratias.
This set of options might benefit from a flow chart. Anyone see anything worth a commentary? That Easter provision for omitting the gradual responsory (responsorial psalm) and replacing with an alleluia psalm–I’ve got that part right don’t I?
Translation of the OCM, 1988 second edition is by Richard Chonak.
Catholic Sensibility 
FWIW:
http://forum.musicasacra.com/forum/discussion/4167/graduale-simplex-and-the-chant-between-the-readings/p1
http://forum.musicasacra.com/forum/discussion/1852/x
More helpful to me was reading Paul Ford’s generous and informative introduction to By Flowing Waters. More interesting is how chant musicians are prepared to utilize and interpret this. When I have BFW in front of me, it doesn’t seem confusing at all–just the ever-dreaded options of the Roman Missal itself.
“That Easter provision for omitting the gradual responsory (responsorial psalm) and replacing with an alleluia psalm–I’ve got that part right don’t I?”
I couldn’t tell from the way you phrased it, but I wanted to point out that the gradual and the responsorial psalm are two separate pieces of music. I only clarify this because I had no idea what the gradual was up until about five years ago. I’d never heard of it (having been born after Vatican II).
Otherwise, this section of OCM doesn’t seem particularly complicated to me. Could just be me, though.