I would be fun if you could move anchored objects with a tractor, but I think that would introduce a whole host of new balance issues.

I'm concerned about the alpha vs mining vessels which are almost always stationary (yes they could move, blah, blah, blah but in highsec their game play is as it should be and im concerned that no matter their defense set up this would 1 shot them).

Basically, a demo charge would be a missile with incredible amounts of damage, but a very low speed and incredibly and/or unrealistically slow explosion velocity.

There's two different things under discussion here so I think I will officially separate them.

T2 "Wrecker" destroyer
Similar to regular destroyers in mid and low slots and stats but has the demolition charge for high slots as discussed by the op. This will be similar to citadel torpedoes with the following differences:

missile velocity: 80 m/s
flight time: 20 s
explosion velocity: 2 m/s

This means maximum range of about 3.5 km after skill bonuses and only useful on immobile targets. It also takes a significant time to hit the target even at that close range.
Total dps of the ship is approximately 2500. It should be considerably stronger than sub caps for killing structures but may not approach the strength of a dread.

This might even use citadel torpedoes with the appropriate bonuses to make these numbers for simplicity.


T2 "Constructor" battlecruiser
This ship will have a number of unique properties:

Extremely short range on all effects.
Module that quadruples the anchoring/unanchoring speed of the target.
Module that assumes control of heavily damaged or offline structures. Offline high sec posses hit by this will have a one day timer after completion of the cycle before they switch.
Near zero range but significantly more powerful remote repair.
Special bay for deployables.

The next idea is not yet approved by the general consensus that seems to be reached by this thread and may be part of the constructor or a different ship.

Turret deployment:
These turrets are not controlled and will simply act based on the owner's fleet settings. That means not purple shoot it or purple rep it.
1 minute anchoring after constructor module is considered.
Active for 15 minutes. May be recharged by constructor module (takes 1 minute).
10km min distance to other turrets.
Turrets only function if the owner is within 50km.
Different types of turrets for damage, mining, ewar, and logi.

This means that a constructor continuously cycling their turrets can have 14 active at any given time.
The exact stats of the turrets is up for debate but as of right now I think roughly:
100 dps damage or rep amount (note that repping is not controlled)
range and tracking to be determined
25k hp no resists
I have no idea what amount is appropriate for mining or ewar turrets

Those stats mean that when fully prepared it is considerably more powerful then most sub caps however it takes the full 15 minutes to prepare it and must be continuously cycling them. If attacked before then it is useless.

It could still be used as an anti-capital weapon even with these restrictions. A dedicated "damage vs deployable structures" role bonus would be better suited to the task.

T3 frigate