Qwix development is still continuing ... it's just that the Dev's don't believe in releasing a new version every week. There is a high standard to maintain, and with external forces keeping the dev's busy, they will be addressed when they are addressed.
If you are having difficulties getting qwix to work, we suggest either making sure you are using an Avalaunch + Qwix combination, make sure your firewalls in SP2 either have Qwix on the allow list or are disabled completely.
If you still can't get it to work .. you might want to try other tools.
As for FTP boost support, last I heard, the author of FlashFXP was trying to incorporate it into FlashFXP but then said he'd have to rewrite his protocal to do so and I think left it at that. you could alwasy head to efnet into #flashfxp and ask bigstar, the author.
For now, I find that creating iso's and extracting them is sometimes the fastest way to transfer many small files .. (like XBMC for example) .. it's not as fast as using a boost enabled client .. but it's many times faster than using a standard ftp client.