Well, if you don't mind, I will provide a few comments without specific quotes:

1) I do not think that companies producing good ASICs would be incentivized to mine themselves on a reliable basis.
There is a large number of operational costs (and risks) that are specific to the miner but not to the party producing the specialized equipment, so depending on legal, economic, and geographical circumstances it may - and often does - make business sense to produce the boards without actually using them.

This is true for a wide array of specialized equipment manufacture - and I don't think there are enough reasons to believe it won't be true for bitcoin.

2) Empirical evidence suggests that current (GPU and a bit FPGA) mining of Bitcoin is not decentralized.

While there are indeed a cute "gold rush" and "side-business" aspects to "amateur" GPU mining, nowadays a number of circumstances have forced the supermajority of individual miners into "pools" (as correctly noted above), a few of which are accountable for the absolute majority of hashrate in both BTC and LTC nets.

When you account for pooled mining, ASICS become completely irrelevant - it doesn't really matter whether there are 4000 corporate-owned ASIC farms or 4 000 000 individual GPU miners, because in both of those cases the equipment will be connected to 4-10 "megapools" which will be effectively in control of the network

It thus appears to me that, if empirical evidence is to be trusted, ASIC resistance (or lack thereof) will have little to no effect on "decentralization", primarily due to very strong centralization arising  from "pool" infrastructure.

P.S.:
My limited understanding of concepts involved suggests that "poolproof" design is possible, but my limited understanding of miner behavior suggests that it would be woefully unpopular.

P.P.S.:
As far as alt-coins go, I would prefer ppcoin and namecoin over litecoin.

Of course, I have my disagreements with ppcoin design, and namecoin is pretty much dead in the water, but at least those two are trying to significantly innovate, as opposed to doing some very meager PoW-algo jockeying and calling it a day.