As the title suggests, an example would be Stealth +5  (+7 in sandy terrain)

Technically no, but I would set it as text in the traits section.

Any chance of a notes field being added as there is for movement, is interesting because when looking at the skills before editing there is a field for additional bonus but no place to add said additional bonus.

I know that a monster homebrew overhaul is on the roadmap, but currently it's basically just the tools needed to support the official monsters.

So instead of a note added to a skill, you'll have to do something like

Sand Veil. The Land Shark has a +2 bonus to Dexterity (Stealth) checks made to hide in sandy terrain.

cool thanks much to both of you.