Lense research- confused

O.K heres the deal. I'm a newbie. Got my 550D a few weeks ago.

I have being doing lots of research on the types of lenses I need to meet my needs. And by lots I mean every evening this week. I'm getting more and more confused so I decided to come back on here as the advice on my previous thread was most helpful

I'm looking for another 2 lenses(and a flash..) to compliment my tamron 18-270. I want some lenses that I can take pictures of family and friends at parties(indoor, low light, possibly even club photography in the future..). I also want a lense which is going to be a wide angle for landscapes. And a lense which is going to be great for indoor portraits of family- baby photography.

So.. currently I am set on the Canon EF 1.4 50mm lense for the portrait. That's pretty much set.

The confusion comes in around the rest of it. Ideally I want a nice wide angle lense that will be great for both indoor group shots and also landscapes

These lenses are on my short-list

Sigma 17-50mm f2.8
Tokina 11-16mm f2.8
Sigma 10-22mm f3.5
Canon 10-22mm f3.5-4.5

I want something fairly wide and fast like the Tokina and I'm drawn to this lense but I'm also concerned about the restricted focal length. Thinking of opting for a fourth lense which would be the sigma 17-50- but is this lense going to add much more to what I want them for than the Tokina alone.

I'm not sure if I am being clear, but as I said, I read SOOO many contradictory opinions

'You don't need a fast aperature for party/bar settings as you will use a flash anyway' vs 'flash ruins pictures, get wide lense' vs 'wide lenses make peoples features look bulbus'

HELP!!!

given your list, i'd suggest the 17-50. the others are good landscape lenses, but IMHO not great for people. If I were going to suggest something not on your list, I'd recommend the 15-85.

i'd look to replace the tamron instead of adding to it...unless you must have the all in one zoom...but something like a 15-85mm paired with a 70-2/300mm or even a 55-250IS would give you better results...

15-85mm isn't going to be great for low-light non flash work...with flash it'll be fine....i'd want wider than 17mm for landscapes myself...

Ditch the Tamron as DreDaze suggests. The Sigma 17-50mm f2.8 can also fill in as a portrait lens so you really shouldn't need the Canon 50 f/1.4 unless you have to have it. The Canon 50 f/1.8 would service as it's very good optically. Don't be put off by it's body being plastic. Treat it like any other lens and you will be fine.
The Canon 85 f/1.8 would be an excellent companion with the Sigma 17-50mm f2.8 even though you didn't mention it.

It all depends how you use a flash as to what results you get... Point it straight at people on full power and 1) they're not going to appreciate it, and 2) it won't look that great... Bounce flash is your friend at events, assuming the ceiling doesn't ruin your plans! Alternatively you can get something like a stofen diffuser which sprays lights everywhere instead of straight at your subject.

If you're going to be doing dedicated portraits or baby shots then you might want to consider more than one flash just so you can play around a bit with off camera flash... There's a lot of advice out there regarding flash, however, I personally don't think there's a definite right or wrong answer. The best thing to do is experiment!

With regard to lenses, you have the tamron... So... Is 18mm wide enough for you? If not, then something like the 17-50/55 isn't going to fulfil all of your requirements. If you're predominantly using the ultra-wide angle (UWA) for landscapes, then you probably won't need the speed of the tokina. The highly regarded canon 10-22 is f3.5-4.5 for example.

As others have mentioned, you will be able to use your 17-50/55 at the long end for portraits, unless of course you want another lens that is even faster than 2.8, then yes something like the 50mm 1.8/1.4 would do the trick nicely.

So I've been rambling a bit, however, I would definitely get a flashgun and a medium range fast zoom (like the 17-50/55). If that's not wide enough for landscapes then you might want to consider an UWA. One of the best things you could do is pop into your local camera shop just to see exactly what these focal lengths look like!