I'm also seeing similar behavior.
Absolutely fresh install of GTA5, loads up single player and I can walk around just fine, no issues.
Ran the 0.49 setup installer, added nothing else at all and launching the game via RPH.exe results in a 10-15sec black screen, followed by a crash before the R* logo appears.
Removed the Plugins folder, same behavior.
No "mods" folder present as I haven't done anything with OpenIV yet.
RAGE Plugin Hook v1.93.1305.16293 PUBLIC
Game: Grand Theft Auto V
Game build: 2628
Branch: Steam
Plugins loaded at the time of the crash:
No plugin was ticking at the time of this crash.
Base address: 00007ff6dc3e0000
Exception address: ffffffffa9f80f0e
Exception offset: ffff8008cdba0f0e
Exception code: 0xc0000005 (EXCEPTION_ACCESS_VIOLATION)
Stack trace (unmanaged):
0x00007ffdba01ff27 - UnhandledExceptionFilter - in Unknown:0 (C:\Windows\System32\KERNELBASE.dll)
0x00007ffdbc6d51b0 - memset - in Unknown:0 (C:\Windows\SYSTEM32\ntdll.dll)
0x00007ffdbc6bc766 - _C_specific_handler - in Unknown:0 (C:\Windows\SYSTEM32\ntdll.dll)
0x00007ffdbc6d209f - _chkstk - in Unknown:0 (C:\Windows\SYSTEM32\ntdll.dll)
0x00007ffdbc681454 - RtlRaiseException - in Unknown:0 (C:\Windows\SYSTEM32\ntdll.dll)
0x00007ffdbc6d0bce - KiUserExceptionDispatcher - in Unknown:0 (C:\Windows\SYSTEM32\ntdll.dll)
0xffffffffa9f80f0e - KiUserExceptionDispatcher - in Unknown:0 (Unknown)
As an aside, it seems to not have this crashing issue, if you first launch the game through steam normally, wait until it's loaded to the main menu, then launch RPH, and once it's hooked to the game, launch story mode.
After that it seems to load into story mode with RPH and load LSPDFR normally (however I've yet to test any kind of extended playtime with this to see if the originally mentioned crash still occurs)