Hi @Edoliviro and welcome to the forums.
Before I talk about each of your requests I would like to take a few seconds to explain a few things that we try to do when making Feature Requests, to make it easier for users to vote on things they would like to see and to make it easier for the developers to see exactly what users are asking for:
Please only ask for one Feature in each post. If there are more than one Feature Request in each post then the developers don’t know which one people are actually voting for.
Please keep that in mind for future requests, if you don’t mind.
Now, back to your Feature Requests -
There is already a feature request for adding an Action by dragging one from a list and dropping it on the sheet, here - Item Templates
Please vote and / or comment on that request if you would like to see this feature implemented.
For your second request I believe that there are two other Feature Requests that would need to be added for this to work. Dropdown input type for character sheets, found here: Dropdowns for stats and Inline editing, which would make editing values on a character sheet more like filling in a web form, instead of using the editor for everything.
At the moment you can use a group of Checkboxes on the character sheet to select which Stat you want to use in the Action, or the select the damage type that will show in the Action. I use something like this quite often with a lot of the character sheets that I have created, and I think the 5e character sheet uses this for choosing which Stat the spellcasters use for their casting Stat.
If you’d like to discuss this further I would like to invite you to join us on the Discord server.