Ok. Rank is based on mp missions, right? I'm about to finish the Level 4 village guild quests. :/ It's working out alright with the jaggi set so far, anyway. Though I need to bring some potions now.
You are doing low rank village quests right now. As you continue progressing, you will reach high rank village quests, the last low rank quest is
, first high rank quest is
. From that point onward, most low rank armor will be a little weaksauce and you'll want to get some high rank armor.
There's a similar progression online/in mp/in port tanzia, from low rank, to high rank, but this time with the additional G rank.
Needing to bring some potions is normal. "Trouble" would be burning through most of 10pots, 10 mpots, 10 honeys, 10herbs+bshrooms, and/or getting one, two or three-shotted. More or less.
There's no rule as to when or how much to grind for armor. I just think that, if I were you, I'd keep going a little bit more before I'd bother. Especially if you can comfortably tackle quests with just a few pots.