I also score very often as the top dps with my Kinetic spec. Damage difference isn't that big between Infiltration and Kinetic. The key role of Infiltration is to burst down important targets. And it isn't that good at it. If you wanna deal some a lot of damage over a WZ, go for a Balance spec, never saw a Sentinel/Marauder score that much.

Flashpoint aren't about PvP, they are "dungeons". So If you wanna PvP, you'll have to go in Warzones (the "PvP instances").

Infiltration and Kinetic rotations are incredibly easy so you don't really have to worry about that. Almost no keybinding change. The third spec, Balance, is very different however, but that's not really the point here (but keep in mind that Balance is by far the best spec for sustained mono/multi target damage). About your questions, assuming full dps gear : Kinetic (Combat Tech) vs Infiltration (Shadow Tech) would be like (of course, anything is just a rough estimation) : 1) How will my opening damage change? -25% 10s is usually enough to throw your first burst with both specs, Infiltration is able to trigger it faster however. 2) How will my burst damage change? -25% With potency+relic+adrenal, an accelerated project followed by an harnessed shadow throw can hit for 10k+ in 3 GCD on a low to medium armored target (I used to sometimes get my 2.5k medal on a TK throw tick, not anymore due surge nerf). 3) How will my sustained single-target damage change? ~-5% Infiltration isn't that good for sustained damage, while harnessed shadow TK throw is really good. 4) How will my sustained AoE damage change? + a lot of % Infiltration can't actually deal any decent AoE damage, while you'll get Slow Time and CT Force Breach. 5) How will my passive defenses change?* 6) How will my active defenses change?* +100% Gotta merge those two, since the healing from harnessed shadow is a key part of your survivability. Change between the two spec is quite huge, Energy/Kinetic damage reduction will go from ~24% to 40%, while Internal/Elemental will go from 10 to 21%. You'll get +6% defense, and a shield (if you use one, I don't) will increase that survivability a bit more. And even if you don't wanna take CDs into account, keep in mind you gain a -25% CD and +66% duration on resilience. And you of course get all that healing from CT and TK throw. And I need to add : 7) How will my utility change?* +200% You'll get Force Pull, an almost spammable AoE slow and the possibility to have a 100% uptime on your guard. TL;DR : You'll losee some burst, a tiny bit of a sustained damage, and will get a lot of survivability and utility. That's why I'm not running Infiltration anymore, only Kinetic or Balance. Mainly Kinetic for PvP. Valor Rank 71 atm.

It will affect some classes/specs far more than others. Some classes/specs have a lot of +xx% crit chance on some skills, others have a majority of +xx% crit damage. The former were stacking surge in order to increase their damage (since crit chance was already high), the latter were stacking crit (cause crit damage was already high). Means that people who were stacking crit won't be affected as much by that change as those who already had a high crit chance and were relying on surge.

Excuse-me... What ?

It's actually more viable than using tank gear. There are a lot of threads explaining how crappy defensive stats are in pvp. Your main defensive stat is your basic damage reduction, which you get from your armor value, talents and buffs. Defense/Shield/Absorption only trigger against weapon attacks (which is great for PvE) but not against spells. And most of the damage you'll suffer in PvP will be from spells. As an extreme example, in a fight against a sorcerer, the only difference in survivability between tank gear and dps gear is that you'll start the fight with a (slightly) bigger pool of HP . On the other hand, offensive stats will trigger on all of you attacks. You're not giving up much survivability, but gaining a huge boost in damage.

Diminishing return on crit isn't much of a concern, it starts hurting way beyond any crit rating you can currently get. It's a real problem only on surge, of which you really don't want more than 300 (which is already too much if you don't have particle acceleration and/or pve 4 pieces bonus). Values given above are a good guideline. Just keep in mind you want some power to fuel your crits.

The most versatile spec is to go kinetic and use some dps gear. You'll get a fair dps (300k medal shouldn't be a problem) and huge survivability and utility. Being in combat technique all the time means your guard can have a 100% uptime, and you get force pull. You'll be able to achieve a better dps with balance spec, which is currently the best dps spec for shadows. Nice aoe dps, the possibility to dot every target around you, and the strongest double/clairvoyant strike of all 3 specs. Worst spec in 1v1, however. Infiltration isn't really the best choice atm since it's the only one that didn't get buffed in the last patch (and it was already the weakest of 3 specs imo). Use it only if you wanna bring squishy targets down fast.

And balance is even better. The only thing infiltration does better is bursting a squishy target.

Works fine for me. Some CC just aren't tech or force powers.

What exactly is solo PvE ? If you mean leveling, pretty much any spec is ok, you got enough companions to play as you want.

I fully agree. This is a great spec with a reasonnable damage output, and still fully able to tank up to HM operations.

Crit is useful for almost all specs, since all get some kind of cit bonus in their tree. Really small diminishing return, so you can stack as much as you want. If you have Adjudication, you'll want as much crit you can get. Surge caps pretty fast, so you don't really need more than 200. Get more only if you have particle acceleration or the 4 pieces pve bonus. Also get some accuracy up to 95%.

Surge has huge diminishing return, using both surge relic and adrenal is pointless. Use power instead. The PvP buff allows to get it quite easily in infiltration spec. Really hard to get ths medal with other specs.

Then I really don't share your experience, I see a lot of melee classes in warzones. And if some melee classes can complain about their lack of CCs, some others really have a lot.