I'll give it a shot....
Home Sweet Home - Looks like you're missing the blue reins, but if the roof isn't too discolored, maybe around $75-100. I sold a mostly-complete one last year for about $50.
Not sure on the 3D puzzle. I don't think it's super rare though.
Maybe about $30 for the waterfall set. It's too bad it's broken (that cloud was designed poorly!) but the box kind of makes up for it.
Ballet Studio: missing pony, pink bunny, and I can't tell if it's got all the dance song cards or not. I'm not sure how to price this one since it's got both French and English on it. The US release might sell for $20-30 incomplete with box, but not sure about the Canadian one.
Brightglow - looks very nice! EBay's ended auction shows she seems to sell for about $20-40. That's a wide range though!
Party Pack Gift Set - this would be something I'd personally be interested in if you ever decide to sell and ship. Could you please tell me if this poster is listed on the box as one of the contents? I would really like to know!
As far as value goes, it's hard to price since there are so many pieces. I didn't see Yum Yum's wings which would really bump up the value. The ponies and accessories aren't too hard to find, but again, this is a Canadian version which is probably harder to find, but I don't know how much demand there is for it. Cool that you have the ribbons though -- those are hard to track down! I would guess this lot here without the poster is worth $60, give or take $10. The poster itself is hard to find. Maybe add another $20-30 for it alone.
Nightglider - if she has no spots, white or brown or otherwise, she's worth quite a bit because she's prone to getting spots. Roughly $60 in good condition.
Not sure on Starlight.
and YES ribbons and combs will absolutely increase the price especially if you can match them up accurately. That kind of stuff is gold to me
Hope this helps! Good luck and please let me know if you open sales to selling to the USA