Siege Tank have new Mealstrom Rounds passibe ability that increase the dmg by 25 vs buildings. It work great and adjust siege mode power properly.
But now Terran don't need to research Siege Mode (save resources&time). Besides its a rule in Starcraft that every not "main" units skill have to be researched (Stormraven Electrostaric Discharge; Stimpacks; Incinerator Gautlets; Lurker morf; Psi Rage etc).
Adding Mealstrom Round as researchable ability in Factory:Tech Lab.
Remove from Dropship tech lab requirment. In Starport with techlab player usually produce BCruisers (it take lots of time), while the one with reactor is not so busy. Besides Starport without any Add-ons (new builded or after flight) Player are unable to create means of transport for his unit in emergency (TechLab take time to be made). Additionally with Reactor it would be easier to create bigger transport fleet in shorter time = more troops can be used for attack = bigger battles = more fun.
2a.Dropship need some tweak. With only transport role it becoming useless after desant. Sometimes is better to just fly over the wall Barrack instead messing with Dropship. We speak about removing from SCV air-units reapair ability and adding it for Dropship.
Ghost Sniper Round deal 80 dmg for organic unit and cost barely 50 energy (Ghost have ~200). With such huge damage few Ghost can instantly kill few of important Zerg units.
Increase the energy cost to 120 energy - so Ghost can kill at most one unit at a time.