Ok, so here are some thoughts:
1. I think it's definitely commendable that you are putting a bunch of effort into finding a good diet for your new kitten. Generally though, it's recommended to stay on the diet he was used to at the breeders for a few weeks or so, for continuity sake and to make sure not to upset his stomach.
2. As far as Royal Canin, I have a very low opinion of that brand too. Keep in mind that many vets have "partnered" with Royal Canin and Science Diet, so they have financial incentive to hawk those brands. And yea, having grains in wet food is pretty appalling imo.
3. Wellness is a good brand nutritionally, and they offer some variety which is nice. Two drawbacks though: Their food often is not the best tasting to cats, and they've had some recalls. But I would say that if your kitten is excited about eating Wellness, then I think you could do a lot worse.
As far as foods in Australia, I'm not sure. This is kind of an interesting one that I've given my cats a few times that seems pretty good:
http://www.ziwipeak.com/I believe that's in your neck of the woods.
To the extent that I give my cats raw food, I give them this:
http://www.radfood.com/But I don't believe they are available in Australia.
4. One other comment about your current diet: it really isn't appropriate for a major portion of their diet to be just filled haphazardly with pieces of chicken and the like. That is because you are upsetting the mix of vitamins, minerals etc., that your cat should be getting. In other words, if half his diet is a commercial balanced meal, and half is some meat, he is getting roughly half of many of the minerals and such that he should be. There are supplements that you can buy to help with that, but it's something that needs to be carefully researched and understood. It shouldn't be done haphazardly.
Also note that in the reading I've done, raw food really isn't recommended as a diet to feed kittens, because of their undeveloped immune systems.
5. The "soft stool" thing can be diet, but it can also be parasite. A pretty startling number of new kitten owners find that although their kitten is up-to-date on "worming", their kitty has come with a parasite that he had at the breeders. One tell-tale sign is if the loose stool is accompanied by a really powerfully bad smell. If that's the case, you may need to take your kitten in to see the vet to have some tests done and possibly some special medication will be required.