I think the problem is more one of how much stuff you try to build in parallel, and how many engineers you allow to help out with construction work. I find that, with current starting resources, I can usually have five or ten turrets of various types under construction while my Spacedock churns out Mark I triangle ships without significant slowdown from lacking resources under the current system, without upgrading harvesters. The problem is more one of convenience - it's easier for me to place a hundred turrets all at once than to put down five now, then another ten a little later, then another group after that, and so on. As such, in the early game if you like to get your homeworld defenses up early (as a precaution learned from the past versions with their hard early game, or for convenience before you forget you didn't put down any defenses and get a wave warning while your fleet is on the other side of the galaxy, or whatever), I expect that you'd place down most of the defenses you intend to protect your homeworld for at least the next hour of the game all at once. Doing this rapidly drains your initial resource reserve, and stalls construction, making it feel like you don't have enough resources early on. With a more limited construction approach (such as 'build fleet first, then build defenses slowly'), you don't run out of resources nearly as fast.
I will admit, though, that I prefer to order the construction of at least my initial homeworld defenses at the start of the game in parallel with my fleet build-up, and simply put up with the out-of-resources work stoppages or upgrade to better harvesters, because that way there I cannot forget to have at least some minimal defenses on my homeworld for when I sent my fleet far away and wasn't paying attention to wave warnings, or just lost my fleet doing something else, or anything like that. Plus, even though I could stagger the defense construction to speed the build of parts of it, I usually wouldn't because it takes more attention to current resource balances and income than I care for. I could do it, and sometimes I do, but not usually.
In short, I think that the main cause of the feeling of lacking early game resources is that most people (myself included) try to build too much stuff in parallel at game start. That isn't something that an increased initial resource stockpile will solve unless it becomes a lot larger.
Now, since I brought up initial homeworld defenses - I usually place down 20 Basic, 20 Laser, 20 MLRS, 20 Missile, and 5 tractor beam turrets for a single-wormhole homeworld as early game defenses, and that increases by about 10 of each of the aformentioned weapon turrets and 5 tractor beam turrets per additional wormhole (within limits - if there are more than four wormholes leading into my homeworld, I'll guard the three or four closest to my command station and put 20 Basic/Laser/MLRS/Missile turrets at the command station instead of 10). For the single-wormhole case, this works out to about 3500 metal and 3000 crystal per second until my turrets complete - before accounting for ships coming out the the Spacedock and any engineer construction assistance costs. So if we assume that we get 6 metal and seven crystal harvesters (I usually have more crystal nodes than metal nodes, while Diazo's test results seem to say it's an even split, so I'm going with a slight skew in favor of crystals), we have a resource income of 420/480/630 metal per second, and 440/510/685 crystal per second, with the appropriate harvester I/II/III research. So if we were to increase the starting resource pool just to allow my initial defense build for a single-wormhole homeworld, the stockpile would need to make up for a missing 3100 metal/second and 2500 crystal/second for the first 30 seconds of the game (assuming Mark I harvesters). The current 20,000 of each would last for about the first 10 seconds of the game, in this situation, not including any fleet construction I might be trying in parallel (which in all honesty is usually a relatively negligible cost - the average resources drained per second over the course of a fleet build-up off of one Spacedock are 79 metal per second and 61 crystal per second, before including engineers, and if I'm not mistaken a pair of Mark II engineers should increase that cost by a factor of about five, leaving the fleet build within income constraints for the early game as long as there isn't too much parallel turret construction going on at the same time).
So, this really begs the questions of how much homeworld defense do I really need to build in the early game and how early I should be building it. In the games I play (AIs at 6 or 7, almost any non-red AI), the answer to how much and how early is essentially "none until after the fleet build is finished, and then start with the setup given previously", as I usually don't see a wave until after a sufficient amount of the fleet has built to fight it off without such catastrophic losses that I spend the next wave interval rebuilding the fleet. However, I like to build homeworld defenses at the start, because at least until my fleet has built out I don't really have anything better to do, and I've forgotten about defenses until seeing the home command station under attack warning in the past when I put off the defense build-up.
Based on the above, I would need roughly 100,000 of each resource in the starting stockpile to fully build out my initial defenses and my Mark I triangle fleet, assuming a single-wormhole homeworld.
