I've been playing the game for a while now, and I've noticed some interesting things while engaging the Tholian Tarantula Dreadnought in combat. I have observed the ship using what appears to be a large AOE ability with a conical discharge similar to that of a Scimitar Dreadnought, only gold in color. Ships struck by this are temporarily immobilized and imprisoned in a smaller version of the Tholian webs created by the Orb Weaver ships. The other ability appears to be similar to the subspace snare ability employed by the playable Bortasqu' Command Cruiser of the KDF faction, in that it instantaneously transports the target directly in front of the Tarantula.
Neither of these abilities are mentioned on the article about the Tarantula Dreadnought on the wiki, and I'm wondering if anyone could provide information as to what these abilities are. I look forward to hearing back on this subject, and wish everyone well.
Just a quick post so you know it's not that everyone on the forums hates you.
I think there's a lot about the Tholians that just isn't known yet, or at least not widely known. They mainly show up in the Tholian Red Alerts that people have been struggling with so much, I personally have only gotten into one of them, and now that I'm at T5 don't have all that much reason to try again. As a result, I know basically nothing about them, even though I try to stay well informed.
That said, it does sound like you have most of the important information on these abilities already, what they do and how to try to cope, so good for you on that count. Best of luck on getting a more helpful response.
BFAW + SST (as told by Branflakes, it combines the two)
Subspace Snare/Disable (basically what you described)
Tholian Web Cannon (also what you described)
Plus standard Engineering powers (EPtS mostly).
Also the CD on both their snare and web cannon are only about a minute, so you will be smacked by them on a regular basis. Also you cannot escape once hit by the web cannon, your best bet being to stay out of the VERY SMALL (only about 20 degrees) firing arc.
The worse part is that you have to be careful when deploying warp plasma. If you even so much as touch the Tarantula, you instantly explode. It is some sort of hull protection weapon, and it will kill you instantly, even if you have 100% shields and hull.