Can I add self-IPs in different VLANs?

Hi,

1. LTM will still do the basic LB features as already said so you're all good.

2. Be careful of auto last hop when on a routes network if it could change like in the case where you have to balance default routes on the network with the direction the traffic came from it can give you a headache. Not saying anything is wrong just consider your networking before making changes.

If you put your servers on the same vlans as you put the f5 then by default the f5 will know where to send the traffic as it looks at layer 2 before layer 3. (So no routing needed it'll just know)

Then after that basic routing or route domains will help you sort out the layer 3 path if needed.

Again just consider the network you're working with and adapt as you need.