Rules for combat actions, bad.
The idea is that you can resolve them in narrative ways. The more codified reality is within the rules, the more you will rely on the mechanics to interpret the results, which leads to a very
gamey experience.
And that in a game! Unacceptable!
I wonder what you think about Rolemaster
Of course a GM may at any time adjust rules, grant bonuses, introduce new checks, etc. if it fits (in his mind).
It's just that if that happens all the time, a wrong system was picked.
So if you want special actions during combat, pick a system that has special actions during combat.
This is the reason in 5e they introduced the concept of advantage/disadvantage. To allow players to roleplay and to reward those that do if their actions are well thought out. Back in AD&D the DM had the option, supported by a rule, to grant a numerical bonus in combat for the same thing, outside of combat clever roleplaying could eliminate the need to even roll the dice.
Again, if you want to eliminate the need to roll the dice, don't use a rule system.
You have to pick a system that everyone in the group is comfortable with. Doesn't matter if that means a shitload of rules or barely any rules. But picking some and then trying to "avoid" it sounds more than just a little absurd. Should've just used another system instead.
I've been playing with GMs that are complete rule nazis (which is absurd and just disrupts the flow of the game, especially in fringe cases) and GMs that try to avoid rolling dice and stats wherever they can (which just makes the players unhappy who want to play by the rules, as they either feel like they are cheating or feel like they have been cheated).
Personally, I don't like giving bonuses for "good roleplaying" other than maybe some more XP at the end of the day. It's just too arbitrary. That's what rules are for - to prevent such arbitrariness.