I found that giving the Graser high burst damage, high flux costs, a long cool down, and a long charge up with the beamfireonlyonfullcharge flag worked pretty well. My numbers need to be tweaked a bit as right now the Ravana with a full Graser load out destroys the Onslaught with ease but is completely annihilated by a Paragon. The biggest issue is that beams are complete useless against good high tech ship without really insane dps, and even then they're not that great. (I made a beam with over 100k burst damage and tried it on the Onslaught and the Paragon, the Onslaught is literally vaporized while the Paragon just shrugs it off)
On the topic of the Ravana, I'd advise a slight boost to the shield arc, I have mine at 180, adding a built in weapon on the front, and tweaking its mobility and maneuvering jets. I used hullmods and a few ship_data.csv edits to do something like this and it made the Ravana much more interesting to fly as. I basically set it up as having high forward burst damage and very good PD (4 dual flak cannons). It was extremely good against low tech ships but much less good against high tech because of its reliance on beams. It also had very high flux all at once from the forward burst weapons (like 10k in 5 seconds) and 6 buffed light grasers that were amazing at at taking out low tech destroyers and frigates supporting the primary target but were horrible against high tech ships. Very strong against single capships but high flux and reliance on maneuvering jets for quick turning, as well as a relatively narrow shield, made it weak to numbers (except fighters, 4 dual flak kills fighters disturbingly well.) which I thought made sense given its description.
On the topic of the shields dropping if you hit hard enough with beams, this happened a few times when I was fighting the Paragon in the simulator and always turned the fight from me getting completely blocked out by the Paragon due to my reliance on beams to me destroying the Paragon in about 15 seconds.
(sorry for rambling about the Ravana, I'm not good at concisely describing ship stats.)