It's good to know the product is appreciated. Thanks for your kind words.
Let's see about those questions:
1. I'm glad the format is easy enough to use.
2. It seems that there is a real need for "profession expanders", so I might consider adding them. This would probably imply additional XMLs where you can add or overwrite parts of an existing profession, so that this kind of tricks can be achieved with ease for advanced users. I have A LOT of features pending, so I'm not promising anything in the short term, but I'll keep it in the To Do list.
3. A custom stat bonus progression could be added. The thing is, I don't know how many people would use it. Stuff like the profession expander in (2) seems to be more of a priority since it would allow more to be done with the system. I might do a poll with the different pending features and see what generates the most interest.
4. The bindings are defined per character, so those are the only XMLs that you can edit to ease the process. Maybe you can do this:
a. Duplicate all skills in the Skills.XML
b. Create the first character and manually bind the skills.
c. Save it and open the XML file.
d. Find the <rankBindings> section in the character file, and copy it to all the other characters.
e. Done. Now all the characters have the same bindings.
5. I've never been able to convince my players to get into TPs. It is totally possible to add a more complex version with skill ranks gained, stat gains to roll, etc. But as I said before, there are so many features I could add to ERA, it is difficult to decide which to tackle next.
Reading about posts like yours, which allow me to know which features are requested the most, is really helpful in helping me decide.
6. Custom DP formula stands with custom bonus progression. I know how I would go about programming it, but there are sooo many other features waiting, that I can't promise it in the short term. You can add negative TPs?
Damn, I thought that had been fixed long ago. Ok, let's leave it there as a "feature" for now...
7. The concept of ranks gained is related specifically to cultures. This allows you to create a human raised in an elven community that knows how to meditate and speak elvish.
8. This is the same that happens by default with RMFRP. Races are given ranks in languages, but to be compatible with other RM books (Races and Cultures and RMU for example) you must see it as a culture that is normally associated with a specific race. See how it is done for Humans in RMFRP: you can choose common man or mixed man, but then you can choose mariner, woodmen, etc. For Dwarves, you would normally choose the same race and culture.
9. Subcultures are a concept from the Races and Cultures book. It changes the skills available to choose from when assigning hobby ranks. I use that book in my group, but it has not been officially offered as an ERA package so far, so RMC and RMFRP rulesets do not allow you to choose it. If your subcultures change the ranks provided for free to the character, the correct way to go about it is to create additional cultures, and name them differently (Goblin-Town, Goblin-Raider, and so on).