NightNGaleX3x wrote:1. Quo quisque est sollertior, hoc docet facilius.
I believe this to be an example of the "the more the better" construction, which are always tricky, so "the more skilled everyone is, the easier they teach." Literally it's something like (in reverse order) "everyone teaches more easily by that (hoc) by which (quo) they are more skilled". It's more usual to have "eo" instead of "hoc", I think, which is why I'm not completely sure.
4. Vix ulli credit, nec quisquam ex omnibus gentibus ad eum accedere audet.
This seems straightforward: "he trusts hardly anyone, nor does anyone from all peoples dare to approach him."
7. Nisi cui imperabis ui illi servo ignoscat, mox morietur.
For "cui", remember that "quis" can mean "any(one)" in certain circumstances, including with "si", so here it's "unless you command someone to forgive that servant, he will soon die". Only "ignoscat" is subjunctive and that's because it's part of the ut-clause in a command. The other two are future indicatives in the usual future condition.
8. Ignoscite mihi, adulescentes, si vobis quid dicam: curae vobis sit ut moribus multarum gentium maxima cum cura studeatis.
"si vobis quid dicam" = "if I say anything to you". "dicam" is subjunctive because it's a future-less-vivid condition, so you could also translate it "if I should say" or "if I were to say".
"curae esse" = "to be something to be anxious about" or something similar, so here it's "it would be a matter of anxiety for you to study the customs of many peoples with the greatest care." "sit" here is "would be" because it continues the future-less-vivid construction (think of "si veniat, bonus sit" = "if he were to come, it would be good"). "studeatis" here is subjunctive because of the "ut" again, but lots of times the English equivalent of such a clause is the infinitive.