I posted this idea elsewhere but...
To reflect the personality of the beast I suggest these ideas.
1 The ranger takes time to bond with the beast, and for his powers to develop. Thus, commanding the beast takes an action from level 3. It's a struggle to impose his will on the animal's instincts.
2 As he reaches level 7 it takes just a bonus action to command the beast.
3 While the beast is uncommanded it may make a move of it's own in combat. The assumption in raw is that the beast "does nothing unless commanded". This sounds like the ball licking scenario. So, I read it as "the beast Dodges unless commanded to do otherwise".
However, remembering it is a creature with its own mind and nit simply an automaton under the control of the ranger, as dm every turn, roll a d6 and consult:
1-3 beast Dodges
4-5 beast Helps
6 beast Attacks
4 When the ranger commands the beast to, eg Help, it will do so until commanded otherwise. This secondary command takes an action or a bonus action depending on the ranger level, as
per the above.
5 Hopefully this gives the ranger PC a sense of times when the beast just did it's own thing and foster a relationship with it so that when it inevitably dies there's a sense of loss...
In terms of using the beast as a mount I would argue it uses normal mount rules.
If being used as a mount in combat, the ranger's move will be effectively taken up by a "using object" rule to steer the beast into combat with his legs etc.
If the beast is hit in mounted combat rule that the d6 beast action table be rolled to see how it reacts.
Does this even make sense? Typing on phone = hard to keep track of thoughts...