Well, you have done what I would do with the weapons - you can always upgrade them (but not to epic). SL are very expensive. Though there are the mission weapons - I know there are some that are reported good Also remember the Omni-directional Phasers. Also, you can easily craft and upgrade mark II Pen phasers (remaining mods do not matter as they can be re-engineered.
Keybindings will help with consistency in hitting the correct keys (set up is a bit of a pain) - Have a look at the League website - I seem to think they have good info on that as well as a link to STO Keybinds software that does it for you .
I really would drop beam overload it is not that effective. The best BOFF spells for tact are: FAW (even though it is snuffed), Tactical Team, Kemocite-Laced Weaponry (level 1 only), Torpedo: Spread (if applicable). Beta attack pattern, Delta Attack pattern at the higher levels are good though I personally try and have one FAW at a higher level as well.
The rest is working on traits, consoles and Doffs. Console wise I try to boost Power transfer, Crit chance and crit severity as my own focuses or use sets that also boost damage (eg House of Martok for Disruptors).