Should I multi mod this?

If by multi-mod you mean vendor, then yes

no

you really want to get a good phys % roll on something like that. Masters will only let you get like 70% or so. better to get that roll first, then master craft.
The level of your melee skill gems doesn't really make that much difference. Spells get a big benefit from level, melee not as much.

multi mod costs what, 2ex?? you can trade for a way better weapon for 2ex on poe.trade....I see stuff way better for just chaos,,..

Thanks for the information, it helped a lot, currently trying to make a 2h axe myself.