Apologies for the bleated response! Other team member here, yes, attacks auto hit if in range unless the targets toughness matches the total damage sum.
That is a fair question. Like in most ttrpgs you roll a d20 and add the modifier to the roll. The modifier being 1 for every 10 of the proficiency in question. You also have the option to substitute the d20 for any other die you prefer.
As for checks involving the HEST score you also gain a modifier of 1 per 10. However most rolls are conducted with a player's proficiency rather than raw stats.
If you have any other questions don't hesitate to ask!
