Problems I have with the in-game shop

I started playing on Outland knowing that there was a in-game shop so no problem with that, I'm just thinking of what the future holds when people can buy full T4-set and surpass the people who are actually playing the game.
If it stay like it is now with T4 released and some trash loot, fine. But if you release T5 then T6 for players to buy without them earning it in-game, you'll loose the core players, and the server will die.

I know there is a income blabla., but watch out so you don't kill the server.

explain how it will kill the server? And by coreplayers, who do you think of? You don't give any valid reasoning, and if you follow the trend from their other servers the shop seems to a part of what makes the healthy population of the server. I don't think you have thought through this one.

Have a look at Icecrowns population. I'm fairly new to Warmane so i'm not sure how long each server has been live for, but 100% of the items are available in the shop. I don't think a day goes by when the server is not capped at 12k.

This has been discussed over and over again. It's non-negotiable. At some stage 100% of the items will be on the marketplace.
I still cannot comprehend why the shop has any bearing over a players gaming experience that doesn't use the shop. If you raid, why can't you just raid with your guild and just do your thing? Hardcore raiders and pvpers will always have better gear than what's available in the shop. So it really shouldn't concern you.
If you are a semi-casual player who still dedicates a substantial amount of time into the server but has trouble downing bosses, and the gear in the shop is surpassing yours, then that's just a damn shame unfortunately.

Once the server has finished all of it's progression and 100% of the items are available for purchase, I'm going to take a wild guess and say the population will still be just as high as it is now, if not higher (if Icecrown is anything to go by).

Warmane has provided another server to those players wanting a truly blizzlike experience with no shop. I suggest either just trying to ignore it, or level a character on Medivh.

The shop is fine. Gear helps to an extent but in tbc the game still revolves around player knowledge, and skill(slightly).