Blacksmithing - Buffs?

[Golaniel]

A few questions as I build up my blacksmithing...

1) Is it worth me getting a Charisma buff to improve my purchase/sellback ratio? Or is the price difference immaterial?

2) Will I have a better chance at skill-up with a Strength buff (as a Warrior) or any other stat buff?

3) Is there anything that will increase my success chance other than raw blacksmithing skill level?

4) Is my blacksmithing level limited to my current level (5 x level + 5), similar to other skills?

Thanks!