.
Oh, and you are not much of a VSD player I believe, which means that you will have problems with this ship.
As for the rest of your points:
The squadron upgrades are mostly a wash for imperials except the one that lets you activate after you move. The intetdictor itself is a poor carrier and relegating it squadrons commands is inefficient and wasteful especially with flotilla s around.
The biggest strength is definitely the engineering value and projection experts plus targeting disruptor will be very good (the only thing so far that warrents it's cost IMO)
It's a good support ship but costing 100+ means there is not enough to support, there Is nothing special about its blocking ability except that it's a 100+ point ship that your likly sacrificing.
It pairs well with gozantis, slicer tools when your running control, repair crew when your running defensive. In fact you probably NEED slicer tools to be effective at control which again leads to the question is 150 points worth stalling 1 ship and slowing a 2nd? (That is the limit of it unless you use konstitine) but again away tarkin, ozzel, raymus, Nav officer/liaisons will all counter your abilities pretty hard and allow your opponent at least some freedom.
Generally the deployment stuff is OK, it effects how they Deploy but often if they deploy at speed 0 so what? It will take an extra turn to start fighting. Unless you have Constantine and are running 3+ tractors it doesn't matter if they start slow (assuming they even Deploy there) it is nice for minefields though.
I haven't tried the grav shift yet since its power comes from being unpredictable so it's less useful against myself but I think it will be great! Able to move obstacles directly into the path of enemy large ships and shift the station to a more beneficial spot not to mention potential objective play.
I didn't build the lists in a fleetbuiler (as they wernt updated yet for the most part) but the first one was a loaded interdictor an isd,2 gozantis and an small fighter group.
The 2nd was 2 defensive interdictir (projector experts) led by tarkin with a vsd and some fighters.
The third (last night) was 2 Interdictors plus a vsd with konstintine and control stuff (tractors etc)
I played the last 2 against 2 isd 2s (not even full lists) for testing purposes and left fighters out of it since the lists would be naturally weak to large fighter forces. Basically even with engine techs the Interdictors were unable to slow the ISDs down and flank them effectively, taking to much fire from the front of the ISDs to be effective by the time they did pass. The third game I tried splitting forces but then they couldn't put enough firepower down to destroy the isds before they died or time ran out
The first list was against 3 vsds and they did better as the interdictor was able to stallout 2 vsds until the gozantis died (they had slicers) at which point the interdictor basically became irrelevant
