SC2Mapster

Thats pretty much the case since the uberlisk tutorial was made for the beta before the campaign dependencies came out. On a side note the unused roach tentacle you will need to create a model for since the model data is there but no model already present (same as several other missile weapons and even some units).

Checked your map found the cause. All your action actors (L2,L3,R1,R2 and R3) have a duped event so the missile is being fired twice per effect remove those to fix it.

Also I advise adjusting the positions/angles of your spine crawlers, looks ugly at the back of the crest.

If you duped the spine crawlers then you are in for a world of trouble as several fields are corrupted with duping. Probably is defaulting to the host unit for the return site which does not exist and not the spine crawlers, try changing Hosting - Host Return - Subject for the missile actor from selectable (defaults to host unit) to the actual spine crawler actor. I already found several important fields in this post.

http://forums.sc2mapster.com/development/data/16774-duplicated-spine-crawler-stares-at-the-ground-when/#p16

For your second question have that on Unit Creation or Upgrade the tendrils are created but have a ValidateUnit term that uses a Player Requirement validator that links to a requirment that counts your upgrades eg. as done with the dark protoss model swaps in the campaign. You will also need to stick the validator into the various effect trees involved in the tentacle attacks.

Answer to your third question is just start from scratch duping is bad and more hassle in the long term than it is worth.

On a side note why spine crawler tentacles? Why not Levithan tentacles or the unused Roach Tentacle or even the Neural Parasite one?