As long as you click the right download link you'll be fine. There is a lot of virus download links which look like the real download link.
I think it's safe, I've had no troubles at all, been using Huzuni v3.5 (for 1.8) and I've had no virus or problems with my account
Huzuni is safe to download, just use the the official website. I've had the client on my computer since 1 year and have yet not experienced glitches or strange things.
I've played with huzuni a lot, and nope it's not a virus. Just click the right link and use the right path. Oh, and don't get caught
Flex can bypass Watchdog (hypickle), GWEN (moonplex), NCP (what skyblock and mineverse uses) and AAC (most servers use this)
Flux, Pandora and Zeus. All of them are paid but if you want a good experience with any client I suggest purchasing one of those.
Personal experience, I did get a virus from downloading the wrong link I believe, but I'm pretty sure it as the right website, but all in all my computer was broken for a month.