1. The program can somehow track the fatigue points? If no, there are plans to implement it?
The current version has no feature to track fatigue points. At least as a starting point, future versions might have a box for fatigue points in the character details in the Adventuring Module, to be manually edited as required. Something like what is now shown for hit points and power points.
In the meantime, I can suggest manually adding a combat skill, and change the ranks of the skill to reflect the number of exhaustion points left. I have never used them, so I am not sure if my suggestion is useful, but that is how I would handle it if required in an emergency during an adventure.
On the other hand, RMU has a different way of handling that, and I might add support for its way of doing things in ERA for RMU, which is currently in the works.
2. The program can somehow track XP gain trough attacks, spell casting, manouvers etc? If no, there are plans to implement it?
There is a feature, not documented yet nor spoken in the tutorials, which does almost that.
If you create an adventure, and play through it, a file will be created in the same directory as the adventure.XML, which contains the summary of actions that could be interesting for tracking XP.
I created it to be simple, since there is too much that might be relevant for XP, but it mentions which maneuvers were successful by each PC and its difficulty, the names of the spells cast, damage received, and tracks who attacked who.
I know it could be made more comprehensive, but each GM would need different functionality here, so it has not been reviewed not spoken of yet.
But, now you asked, and now you know it is there. Please try it out and let me know what you think.
3. At the current state it's impossible to add the Arcane Realm to the system through customization, why that conflicts with the rmfrpCharacterLaw.professions.era file bought, right? there are some workarounds, other than manually re-write all prof.xml files? same if i add new arms category... right??
The current version does not allow adding additional categories without requiring a complete new set of professions.
The next version I am working on corrects this, by giving a cost of 0 to any skill or category not mentioned in the profession.
I am not releasing it yet since most of the work in that version is for the preliminary RMU ruleset.
If the inability to add new categories for existing professions is blocking the current users of ERA from playing, I could try to release an intermediate version including the fix.