Hi,
The last public FP available for Warp 4 (without a SWC subscription to bring you up to 4.52) is FP15. I think there was a FP16 and 17 for folks who had paid support.
There is a public device driver fixpak 2 that can be installed (they'd separated the drivers out by the time of FP15), but honestly - if it is working then you probably don't need it. If you do want it, you can get it here:
ftp://service.boulder.ibm.com/ps/products/os2/fixes/ddpak/xr_d002/For those with paid support there is also a Device Driver FP3.
The newstack.zip file mentioned will fix some TCP/IP bugs / crashes which could happen with mpts 08621. It makes the TCP/IP networking more stable, but if you're not experiencing any crashes then you might not want to bother installing it. To find out what TCP/IP stack you're running, type:
inetver
and it'll tell you. I can't recall what newstack.zip brings it up to off the top of my head and right now I'm not at my Warp4 machine.
If you're running Peer, there is a Peer fixpak at:
ftp://service.boulder.ibm.com/ps/products/lan/fixes/ibm.peer/english-us/ip08414/Of course there are the other standard "must haves" for OS/2 that I put on just about every install, items including:
-DANIS506.ADD driver (get rid of the ibm1s506.add driver)
-EMX Runtime
-info-zip and unzip
-The various libc / gcc runtimes (for running the later builds of Firefox)
-Warpin
-re-activate the launchpad
-Watchcat (along with the following)
-xf86sup.sys (from xfree os/2 - allows the death process killer for watchcat to work)
-death9.zip (there are times when a process hangs that only this can kill it)
-Dossleep (I can't tell you how many times this has come in handy in CMD files)
-Uniaud (although I don't know if this would have any use on Virtualbox)
-Various USB drivers (but you've mentioned you don't really care about USB)
-Fat32 ifs driver (useful for all those flash drives formatted with fat32, but if you don't care about USB, then this may be pointless too)
Back in the day I used to also install the win32s 1.25a windows 3.1 update and the Windows media player / multimedia update add-on, but now days not so much.