Klingon Augments was a good story, in the sense that it was a follow up to show that the Augments arc earlier in the season had lingering consequences. Ideally and logically, Klingons would come up with the Augment ideas on their own without human Augment involvement, and the creation of Klingon Augments would have played a significant role in helping the Klingon Empire conquer and expand, but the writers did not have the time to develop such a story. A Klingon Empire version of the Eugenics Wars seems like the kind of idea that could last a few seasons and ENT didn't have a few seasons to spare.
As for explaining ridges, even though the answer given in the series makes sense, the Klingons having a large empire and different houses mixing with other species over centuries should have been a logical explanation on its own to explain why some Klingons had ridges and other Klingons did not. That and the Klingons treating their ridges as something sacred unworthy to be seen by outsiders.
"Bound" was a campy nod to TOS. ENT could have used more Orions actually, so I’m not opposed to this episode at all.
IAMD was just fun to see everything flipped upside down. It was nice to see the underdeveloped characters come out on top in the MU too.
Riker's episode, as a part of this sequence of offerings, would have fit in nicely. And been a welcome addition. It might have been a deplorable series finale, but would have been satisfactory as a midseason episode.
If that story was placed as the final episode before the Terra Prime two-parter, and had the appropriate edits, it would have fit perfectly in the season.
I feel like fans missed the point of what Enterprise was intended to be. It was not conceived as birth of the Federation, but rather as simply early days of Starfleet. the first Enterprise, the first ship to go fast enough to zip around the galaxy. Season 3 saw the show retooled to the Xindi saga. Season 4 saw the show retooled again, forshadowing the Federation.
Considering that the show was expected to go seven seasons, and the show was set ten years before the founding of the Federation, I understand why some fans think that. If the point was a look at early Starfleet, it could have been set 20 – 30 years before the founding of the UFP, away from any expectations to show how the Federation was formed.