Power Combos

yes

Yes, it seems like they now allow tech powers to combo with biotic and vice versa. I for one appreciate this change, because your makeup will no longer hamper other players (I usually play tech, and I'm sure my Overload pissed off a lot of biotics who were trying to set off combos in ME3). Supposedly, Bioware is trying to get players to be more cooperative and less "rambo" and it shows in the point system where I didn't see huge discrepancy between the highest and lowest scoring in the team. Let's see how this plays out in the coming weeks...

I'm on the other side of the fence. For me it sounds like dumbing down the combo mechanic and it feels anti-teamwork since now everyone can spam whatever the hell he/she has.
I enjoyed picking up classes and builds according to what others have picked. Now I can take whatever.

It's a change in the direction of 4 simultaneous solo runs, not 4 players team.

Power recharge speed seems rather long compared to ME3, which will lead to less combos. All of the videos I've seen have shown both weapon slots occupied...can anyone confirm that we will be able to use 1 weapon if we want to remove the second for cooldown reduction?

On the xbox one what button is used to switch weapons?

Looks like the Krogan Engineer has the same abilities as the vanilla Human Engineers in the ME3. However, while watching a stream of someone rotating between incinerate and overload, it didn't seem like overload primes for a tech combo anymore. Overload definitely detonates a fire explosion, but I didn't see any tech combos from the follow up incinerate. Can anyone who has played the game speak to this and/or any other changes to power combos?

Yes, and no.

Yes, it makes it easier to pull off combos, but remember that it was already easy for everyone in ME3 to spam combos when they introduced the ammo mods to Multiplayer, since Cryo, Disruptor, & Incendiary rounds all prime enemies. Remember how pissed people would get when you would just Incendiary + Overload everything, which messed up their precious Biotic combos? Problem solved.

On the other hand, not all kits are capable of priming targets. Since there are so many detonators this time around, priming powers become much more sought after. Unfortunately, not all kits have access to powers that prime (from a quick glance, only about 60% do), which means team work is VERY crucial....but you also don't have to worry about a teammate ruining a combo by using an incorrect detonator.

Give and take, basically. That's called balance.

Overload for the Krogan Engineer is now just a detonator and not a primer, which means the Krogan can only set of Fire Combos with the Incinerate as the primer as well as Cryo Combos if the Assault Turret is specced to use Cryo ammo (rank 6 unlock on that tree).

Kinda disappointing that Overload cannot also be a primer as that would have given him access to every elemental combo, but 2 out of 3 isn't bad.

Overall he's a pretty good kit to use.

Having played some more of the Krogan Engineer I can say it is actually possible to access every elemental combo, just you cannot self detonate Tech Combos.

Overload is a detonator and not a primer BUT the very first frames do actually work as a primer... you just don't have enough time to detonate it yourself before it ends. If you're playing with a friend though he/she can detonate it for you. Had two of us playing earlier with me as a Krogan Engineer and him as a Krogan Vanguard. If I Overload and him charge in sync it'd then cause a Tech Combo.

So will a power evolution to detonate or prime replace it's original setting, or expand upon it?

But max "reduction bonus" to cool down is now 100%. I.e. equipping a very light pistol for example you can see the weight bar be well below threshold and the bonus stays at a 100% If i equip an assault rifle for example and keep the weight just at the threshold i still get a 100% bonus. 

It seems they really shifted the focus to weapon dmg. at least seems like it at early levels.

Just upgrading the skills will do alot for your performance. We also have to consider that XP gain is different than ME3MP. Mods will also go to rank X (eg. 10) - so things like Barrel mod (+damage) will give 25% boost to damage on it's own. (I have Assault rifle barrel 4, and it gives 11%)

Plus the whole idea behind the prestige stats, that apply to all your characters - a decent upgrade can be expected there as well.