Sorry for being silent for too long.
1. PKZIP (official zip standard) supports files over 4 Gb in a somewhat freakish way: with Zip64 extensions (and normal values for sizes stay at $ffffffff if I remember). It's very rare thing nowadays, and no wonder it is not supported by FAR (trying to browse such a file triggers the error).
2. Far allocates much memory for editing. Pressing F4 on a big file (I don't remember if it was bigger than 4 Gb or not, in each case Far should have tried to allocate too much) triggers instant death (no warnings, just no far) at some point. Few checks should help.
3. I looked at russian forum (sorry, I managed to miss it first time) and realised, that many worries of mine (not the two above) are mentioned there. If I will write something sometime, I'll write it there.
4. Are these things unintentional:
* when I view my program with comments in russian, codepage isn't detected correctly (well, something has changed from beta 4), why doesn't it choose by default current console codepage?
* why does it try unicode mode for viewing files too often?
* when I view hex mode, starting view doesn't put spaces between bytes (like 0000000000000000 | 0000000000000000), after changing anything I can get only 00 00 00 00 00 00 00 00 | 00 00 00 00 00 00 00 00. I use console mode with width >=160.