Heh, I must admit that when I first bought Beast Wars' Armordillo vs Snapper, I used the Volcano Base as Mt St Hilary in my G1 toyplay (and pretended the base section was part of the Ark ).

In terms of viability for Hasbro, I think these could work as Cyberverse playsets. The vehicles/bases could 'fold out' into a play set, similar to the DotM Ark w/ Roller. So you could have say...
+ The Ark (G1 cartoon style) w/ Legion Class Autobot who transforms into Omega-Delta Class Shuttlecraft
+ The Ark (G1 comic style) w/ Legion Class Autobot who transforms into Ark Shuttlecraft.
+ The Nemesis /w Legion Class Generations Megatron
+ Autobot City w/ a repaint of Generations Scamper (or a Legion/Commander Class Metroplex if they wanted to go there)

As for the Space Bridge... a G1 comic style Space Bridge would be spectacular, and it could transform into a robot resembling Spanner. A G1 cartoon style Space Bridge would be more challenging to design as a toy that would engage kids, cos let's face it... it's pretty much just a purple doughnut. Mebbe the toy could just be based on the G1 comic Space Bridge, but its robot mode weapons could assemble to form the G1 cartoon style Space Bridge. Alright, I know the incredible irony of Spanner having weapons... maybe market them as "tools."

Other things I'd like to see would be...
+ Axalon w/ Legion Class Optimus Primal (Cybertronian w/ vehicle mode - repaint of Legends CYB OP)
+ Darksyde w/ Legion Class BW Megatron (Cybertronian w/ vehicle mode - retool of Legends CYB Red Alert)
+ Steelhaven w/ Legion/Commander Class Generations Fortress Maximus (based on his IDW model )
+ Galvatron's Flagship (from TFTM and G1S3/4) - w/ Legion Galvatron. Base mode could resemble the throne room where Starscream had his coronation
+ The Lost Light w/ Legion Class Rodimus (slight repaint of previous Legends class figure)
+ Yukikaze w/ Legion Class Leo Prime
+ All-Terrain Turbo Transport w/ Legion Class Grimlock
+ Autobot Bird of Prey w/ Legion Class Ratchet (or any other Autobot). The G1 coloured version could be a regular type, then make the Universe variant a limited exclusive (it'd come w/ a redeco of Legion class Trailbreaker^cutter).
+ Xantium w/ Legion Class Generations Springer (or any other Wrecker)
+ Decepticon Heavy Transport w/ Legion Class Bludgeon or Spinister or any other Mayhem.
+ Warworld (yyaaaaah!!) w/ Legion Class Bludgeon or G2 Megatron
+ Twilight w/ Legion Class G2-accurate Jhiaxus
+ Quintesson Cruiser; could also transform into a Quintesson Warship (bulk of the vehicle is fairly similar) and open up to form the Quintesson throne room with faux Sharkticon pit. w/ Legion Class Quintesson or Sharkticon (latter may be more marketable to kids). Comes w/ missile launcher that shoots missiles resembling Lithonian Shuttles^Quintessons' Trident Attack Craft.
+ Decepticon Bird of Prey w/ Legion Class Thunderwing. Base mode should have a small section for torturing Autobot POWs.