Homebrew channel with WiiKey

It is safe to install HBC on a WII with wiikey 1.9? (my wii actually is 3.4U)
Can i upgrade the system menu to 4.3 throght nintendo oficial sources?
Its better to upgrade then install HBC or install then upgrade?

Software-wise it should be safe to update but I can't help at all regarding the wiikey. This is not a modchip support forum.

I've got limited experience with modchips but I believe the wii key is unaffected by the wii's system. You should be able to update normally with now problems.