Cross class skills for Marauder solo play?

[Maelwys]

If you're trying to do damage, you may want to instead use damage buffs in place of a few of those.
I'd suggest Raging Strikes, Internal Release, Blood for Blood and Invigorate in place of Virus, Haymaker, Feint and Venomous Bite

I can understand a DPS-build Marauder using Blood for Blood and Raging Strikes/Internal Release/Straight Shot/Invigorate though.

The list with question marks against them were "suggestions", but I'd not leave home without the above skills on the bar.
Just be careful of 'Blood for Blood' if you're soloing - more damage to the mob, but more damage to you!

(it might also be worth levelling your Chocobo up if you're soloing outside of instances - it'll keep you healed and contribute to DPS noticeably!)