Weddingbee boards

I am giving the toast at my sister's speech and I want to thank my parents since they are paying for everything, with very little contribution from the bride and groom and none from the grooms parents. Is it rude of me to just thank them? I want them to know how kind it wis but I don't want to be rude, especially since I am their daughter and I don't want people to think I am purposefully slightly the grooms family. Perhaps I am just overthinking this since I am not a huge fan of speaking in front of audiences... but would something along the lines of "First I would like to thank everyone for coming to share this special day... and I'd also like to thank my parents for hosting this wonderful event." Then continue on with the rest of the speech. 

I was considering thanking his parents for raising the groom, but honestly they are both quite immature and he pretty much raised himself and his siblings... Should I do it anyway even though it isn't sincere? 

I really don't want to step on any toes. Would it be better to just let my parents know how much I appreciate it before or after the wedding? Even though I'm not the one getting married, but because they are paying I get to see lots of family I haven't seen in a while.

Sorry for being a bit long winded.  

That is such a cute idea- thank you very much!