Makbar, the game play will slow down only in regard to certain resource acquisition mechanics (trade and refinery ships now travel longer). It will of course, take longer for fleets to travel to places, so smart use of forward bases and production facilities is also needed. This gives more significance to making raids on enemy territory, aiming not to take planets but to simply cripple their offensive capability. Imagine you take out someone's frigate factories at the battle line and the nearest they have is four jumps back. In that sense I am also thinking on increasing the build time for certain structures, which would in turn make their protection that much more important, since you couldn't have another one two minutes later, but that will have to wait for beta playtesting to see what people think. I don't want to slow down the game *too much*. 
When it comes to planets, an early rush is still possible, but this time - more realistically I might add, the more you expand the more vulnerable you become. Keep in mind, you can make blockades in a system, using new interdictor abilities all factions will have, together with static phase inhibitors. So you can make a forward base which acts as a wall against enemy expansion, you just have to study the map, find a chokepoint and fight like hell to acquire it and keep it.
Fleet positioning, as I mentioned, will also be a must. Should you lose your fleet, or the enemy breaks through to your rear, you need to have means of getting your ships there - if all your ships are in enemy space, it may take too long for them to backpedal to wherever they are needed, costing you valuable colonies and structures. Keep in mind that the bombing damage has been tweaked, it does take slighly longer for colonies with fortifications upgrades to be blasted into dust.
The Xin will have a special mechanic in place to help them combat the fact that they will always be outnumbered - they move *very* quickly in phase space within friendly territory. The only problem they will have is with sublight speed, so a Xin commander will have to pay extra attention to where exactly are their ships.
Makbar, yeah, the AI being not so smart you can use lots of cheap tricks on it. For example, you can jump in with a small fleet and drag the huge enemy one away from the starbase, for example, then blow it up with a fireship group. The Xin will have a more straightforward approach - just go in with capitals and nasty drones and smash everything. 
Spamming is a term referring to a tactic where a player repeatedly performs a same action in quick succession. As a game term, it originated with the old 2D fighting games like Mortal Kombat, where you could win a round by pressing a single button many times. With strategy games like Sins, it means building the same unit over and over again and thus overwhelming your opponent because no other unit is that useful.
