Alas, if only I had 7k mustered at the start of the war and any fortified systems in which to bleed his fleet.
That's alright; under the existing game rules, you couldn't put together enough of a fortified system to bleed an enemy fleet outside of (a) the very early game and/or (b) mods. Except for first-war strategies at the point in the game where a dozen corvettes comprise your entire fleet, fortifications are the victim of a positively Pattonian outlook: they don't scale to fleet power well, they cannot be concentrated in sufficient force, and non-hyperlane empires can typically trivially bypass them. The only real thing you can manage is the strategy that Paul suggested and you already tried.
I'm a bit ambivalent on how much the new game mechanics will actually work around that. You probably won't get *that* substantial a boost to firing speed, given that the only evidence we have (one datum) suggests that at the present scaling, you need to be outnumbered a hundred-to-one simply to double your fleet power. Merely being outnumbered two-to-one doesn't necessarily translate to that much of an advantage unless they used a logarithmic growth factor (and why would they?), and it won't count at all if your fortified border outposts already make up the strength difference because it scales by combat power in action rather than number of ships. Forced hyperlanes, FTL-locks, and planetary fortification changes will prevent enemies from bypassing your planets, but that's a sword that cuts both ways. If you can't bypass their hardened frontier planets, how can you raid their nougat-filled interior? It all depends on how powerful those fixed fortifications actually are, and we're very short on actual numbers on that front. Being able to build X defense platforms is all well and good, but if those defense platforms are as good as corvettes in an era of battleships, that's no better than what we have now. I fear, hopefully groundlessly, that the net effect of the new changes may actually reduce the hitting power of smaller empires on a strategic level. Given that my typical approach to dealing with early-awakenings is to cheese the AI as Hanzoku suggested, that doesn't auger well.