Is this character suboptimal/viable?

[Nymrohd]

Well do give fighter multiclassing a thought. At some levels paladins have very weak or even no Str attack. Plus the extra Str at will, and if martial power is in play access to Combat Superiority are really worthwhile.

 

[arcseed]

Or consider cleric multiclassing, for that matter. Righteous brand is amazing (though perhaps not worth giving up Certain Justice), and picking up Divine Power at level 10 instead of one of the L9 charisma dailies would be pretty sweet.

 

[Mallus]

Another piece of advice: take the first Warlord multiclassing feat: Student of Battle(?). More healing is nice (1 daily use of Inspiring Word), plus you can train Athletics, which is handy in a number of situations, especially if you're grabbed.

 

[FreeTheSlaves]

I am considering the multi-class feats, just not at the expense of the paragon path. Fighter/Warlord are the obvious choices. Cleric doesn't fit so well thematically and I'll get punished skillwise to boot.

Yes, I am developing an eye for training up athletics in particular. Extra leader or offense do appeal almost equally, I've got a hard choice to make here I think.

 

[Kirnon_Bhale]

There are a ton of multiclass feats for martial characters now. I think however once divine power comes out you might find a suitable alternative for your dump at-will which you can then retrain.