Are level milestone roles free?

Yes. Level milestones are part of the free features.

Can I stop certain channels from giving XP?

Yes. Blacklist any channel or role and members will not earn XP there.

Reward activity with XP and levels. Members earn XP from messages and voice time, unlock roles at milestones and climb a leaderboard you can style.

Message and voice XP
Members earn XP for chatting and for time in voice channels. Both can be switched on or off.
Level milestone roles
Give a role when members reach a level. Level milestones are free.
Rank and leaderboard
Members check /rank and /leaderboard, and the leaderboard styling is configurable.
XP blacklist
Keep spam-prone channels and roles from earning XP.
Staff adjustments
Add XP or set a member's level directly when you need to correct something.

Are level milestone roles free?: Yes. Level milestones are part of the free features.
Can I stop certain channels from giving XP?: Yes. Blacklist any channel or role and members will not earn XP there.