Does the DPS(DAMAGE PER SECOND) mean how powerful a weapon is?Because I try and pick the weapons with the highest DPS.Pulswave weapons seem to have the highest which I guess is because their basically 25th century energy shotguns.Or am I wrong about DPS meaning how powerful a weapon is?

DPS is damage per second, yes. The higher the better, but sometimes you go for the effect or firing arc instead of pure DPS.

Of course, some torpedoes have low DPS but high one-shot damage. If you have them set to manual fire, they CAN be better than a higher DPS auto-fire torpedo. It depends on your timing.

DPS refers to the AVERAGE amount a damage a weapon dishes out... It doesn't factor in play style or environment effects...

In open terrain, someone could start sniping at you with a Sniper Rifle well outside the range of the Pulsewave, forcing you to run up into a hail of unanswered fire to get into range... (And if your opponent is expecting this, and has a nice mine field or turrets deployed...)

DPS is one factor, yes. But there are weapons with lower DPS that are more ideal (cruisers having beams instead of cannons, or a one shot kill tricobalt holding ship), but to keep it simple, if all you want to do is point and shoot, and not worry about strategy much, DPS is the main you should look at

There are, as others have already mentioned, a variety of subtle considerations when it comes to weapons, both in space and on the ground.

Overall, in terms of which skills or even career/ship combinations to pick there are also considerations.
As an example, I fly an escort as an engineer, and enjoy it much more than I did as a tac.
I do less DPS, appreciably, but because I can almost tank I can hang in fights, both PvP and PvE, for much much longer, escape bad situations more often, and outlast nastier beatings in general; I have a higher kill/death ratio by far.

Some things to consider with weapons;

Ground;
Remember each weapon choice should be in light of your kit powers, captain powers, play style, and other weapon choice.

One might not initially find a shotgun useful, others will try to keep you at a distance where its no good, particularly using sniper rifles to accomplish this.
But pair it with a stun pistol? And stun someone as your opening attack, then close and fire the shotgun?
*whistles*

Space;

A tricobalt torpedo is crap for DPS in the sense that it has an insane reload time and high rate of failure if you hit a shield facing.
But if you have an agile ship, a quick trigger finger, and AP beta it can be a devastating closing move when dropped on a shield-less quadrant.

In the same way, quantum torpedos have slow reload times as compared to rapid reload transphasic launchers, or photon torpedoes.
But they kick like an angry mule on steroids, and are much easier to aim/fire than Tricobalts, and the reload time isn't terribly bad.

Escorts therefore tend to see better results with Quantums than Photons because we are agile, fast, and tactically enabled enough to turn them into something truly nasty.
Torpedo High Yield III and a mk XI purple quantum supported by consoles are definitive battle-enders if saved up for just the right moment.

What about shields? Does the Max Shield Cap mean less damage taken? Again I always choose the highest MSC.

Generally, yes, shield capacity is the main thing to go for in both PVE/PVP these days... resilient shields are a close second (less bleedthrough). Regenerative not so much...

True. But like Regenerative Shields if I am using a Sci ship for its Shield + power. Also goes well with energy draining abilities and general Shield Buffs. Otherwise, yeah Cap is a good choice.

I've heard it said though, that even once the bug is removed that a MACO set is better than Aegis or Borg for an escort even though it has a somewhat lower shield capacity.