@Starstriker 1:
No, I'm running tax/morale at just over 41% approval for the tax income. I have trouble keeping morale at 100% during the colonizing/crash phase of the game, unless I'm getting really lucky with finding cash-producing anomalies. Maybe I should try ramping it to 100% for just a few turns here and there, right after I've discovered a cash anomaly or sold a tech, and can afford to "float" for a few turns? Might help.
That's your problem, then. 41% approval doesn't get much population growth at all. You have to go past the 70% mark to get appreciable population growth, and 100% gets you the best bonus.
I actually run with taxes down to nothing (or nearly nothing) from the start of the game, up until I can't concievably keep doing it with any kind of safety. I do this in lieu of quick buying (for the most part) and it can work very well, especially if you get lucky with anomalies. At the start of the game, it's really a no brainer: your costs aren't that high and neither are your taxes. Therefore, you should try and reap the benefits of high population growth.
I've found that it has its pluses and minuses. On one hand, there's the aforementioned lack of quick buying which can mean getting less colony ships and constructors out in that crucial early part of the game. Another is that you have to be very careful with how you balance your economy during this stage. Every lab and factory that you aren't using is costing you for maintainence, and if you over extend yourself in that regard you really cut short the amount of time you can run at top morale.
On the other hand, when you DO start taxing your people (preferably when your planets are getting close to topping off in population) you get an appreciable amount of money earlier than you would otherwise. I honestly can't imagine going without it... taxing your starting population early is really bad in the long term. Short term pains need to be taken for long term gains.