Unless the attack bonuses has changed since third on the wii, AUx is almost always better than critical eye/expert.
Sharpener is nice but personally I go for razor sharp and when I need to sharpen I just flash/sonic bomb, or wait for a break in the monster's attack pattern.
Here is a short list of useful skills available early on:
AUx (if attack vs crit is unchanged from tri)
Elemental attack up (DSs can have some pretty high elemental effects, may need to look at a damage calculator to see if RAW or ELEM on a particular beast is best)
Evasion (more invincibility frames = goodness)
Razor sharp (so many things are effected by weapon sharpness)
Earplugs (cause you don't have a shield, with practice you will be able to dodge the roars with evade)
Psychic (wonderful when going up against monsters like Aggi and Gaan)
You can get elemental and status skills from food, but considering how often you proc from the shear amount of attacks per second it can be overkill. That said Status up on armor sets is also a solid choice (4-5 paras per fight depending on how much health they have, monsters stay poisoned, etc.). Constsution skills are nice but I always end up with 2 or 3 dash juice per R.Luddy kill (an can kill it in a few min) not to mention you can get them from Hunters for Hire and the boats.
Currently I run around in volvidon and have AUL and Evasion 1 (found a nice attack charm), using bloodwings the raw damage coupled with the poison damage makes elemental weakness a non issue. I live in fear that someone will see what I am doing to these poor beasts and report me to PETA.