Just a couple of notes on the latest additions:

Chaha:
I gather you copied the beginning text of your Chaha page from some text you'd already written for Silt'e. In the second sentence of the first paragraph, you still have "Silt'e" where you (I assume) had intended to replace it with "Chaha".

I don't know what it really adds to your presentation for Chaha, but you might be interested to know that "Sebat Bet Gurage" means the "Seven Gurage Houses" referring to the seven recognised groups that make up the Gurage.

Chakma:
It's true that Chakma script developed from Brahmi, but it's also very clear that it is most closely related to Burmese script and their common ancestor Mon, then to Kawi of Indonesia (and its two descendants Javanese-Balinese and Sundanese) and then to the Khmer-Thai group. All of these descend ultimately from Pallava script (most likely a simple, non-monumental variety) introduced from Southeast India with Buddhism and by that token, their closest Indian relatives are the Telugu and Kannada scripts.