It seems like the pve is going to require a bow, or nearly so.If you must have a bow then its harder to fit in more than 1, maybe 2 melee weapons (2 if you sacrifice in other skills)
There is no one forcing you to use a bow though, you can very easily fit 3 weapons if you don't use a bow.
And by having only 1 character, people will be trying to fit creature control for pet points, controlled riding, and maybe taming, etc. so I think unless pole weps become OP fewer people will be carrying multiple weapon skills.