Good thread start. The Bellator tournaments are starting to take shape even though there haven't been many official announcements about their fields yet.
Some comments on your field projections:
Mello - that's a good suggestion. He looked great against Sharipov. He ragdolled him and showed some nice dirty boxing. He's won 5 straight now and I think he could surprise people at 135 because he fits their better w/ his reach (62.5") and lost to some real titans at heavier weights.
Riggleman - I don't think he should get an invite. He only won a split over the aforementioned Sharipov and you don't want a guy in the tournament who lost to a TUF participant (Dodson) even if he was the champ.
Weedman - dropped down to LW, but think he'll be a prelim guy/Feature fight guy in the interim.
Held - he qualified for the FW tourney.
Spoon - he a FW too.
Radley - yet again, think he's a FW. He originally joined for the FW tourney.
Cooper - he's a warrior and who will give just about everybody problems, especially those who are reliant on wrestling.
Rickels - Cooper-esque
Steinbess - not good enough
Baker - worn out his welcome for time being
Ford - don't know if his offer still stands after losing outside the org.
Costa - think he needed to win a qualifier at least.
Other members of the roster that I think are better options than fighters you listed - Thiago Michel (155), Cupcake Woodard (155), Dave Jansen (155), Sapo (170), Karl Amoussou (170), Jonas Billstein (185), Vitor Vianna (185), Brian Rogers (185), Norman Paraisy (185)
I would like to see M'Pumbu drop to 185 and vacate the belt, but doubt it'll happen.
I'm sure there will be several more notable signings before now and March still. Holding out hope for guys like Miguel Torres, Mamed Khalidov, Paul Daley, Gunnar Nelson, Alex Sarnavskiy, and Hacran Dias. I heard there was another major signing from Japan (like Ueda) yet to be reported publicly.
From the names we do know, my favorites would be:
135 - Ueda
145 - Bezerra, although Spoon is close
155 - Tirloni
170 - Good, Pereira is close
185 - Falcao
FWIW I got 2-3 pre-tourney picks (Dantas, Lima) right for season 5, and picked Big Monster to win HW so it'll probably end up 3-4.
Once again, good topic.