[ZeonOne]

Strength does not increase critical in shotgun. Here is a quote from Zenith.

Zenith Wrote:Each weapon has it's own critical hit chance and critical hit damage range. The best way to land more crits is to pick a weapon that has a high chance of a crit (like the razorwhip), improve your weapon skills, or be lucky.

If you are lucky you don't need the other two.

As far as weapon cap limit, there was one a long time ago. It was true that the melee weapon does not have a cap limit while the range weapon does. However, with the introduction of Skill, everything was changed.