Thanks for the feedback. The first two issues are bugs and we will fix them.
For the third issue: if you log in to Keychat using your own microblog ID, you can receive NIP-17 and NIP-4 DMs in Keychat when others send them to you. You can already reply to NIP-17 DMs in Keychat, but replying to NIP-4 DMs is not yet supported.
For the fourth issue: some mints charge fees. If Keychat receives one ecash token at a time, it becomes inefficient, so we batch multiple tokens into a single receive operation. We will improve the receive-stamp mechanism later.
“As an example, we construct a transaction spending 3 inputs (Proofs) from a keyset with unit sat and an input_fee_ppk of 100. A fee of 100 ppk means 0.1 sat per input. The sum of the individual fees is 300 ppk for this transaction. Rounded up to the next smallest denomination, the mint charges 1 sat in total fees, i.e., fees = ceil(0.3) == 1. In this case, the fees for spending 1–10 inputs is 1 sat, 11–20 inputs is 2 sat, and so on.”