As for your original question, I don't think that your ASPI problems are normal.
I've just checked my 98SE laptop, with only the internal IDE DVD-ROM drive installed (i.e., with my external burner disconnected as in your typical configuration).
Recall that I only have the original 98SE ASPI, so that Nero InfoTool | ASPI | Nero ASPI says "ASPI is not installed". Still, I have no problems in calling up Nero itself, Nero CD Speed, Nero InfoTool, KProbe or MInfo.
In particular, the only Wnaspi32.dll on my HDD is the original 98SE file in C:\Windows\System (under 98SE, Nero doesn't install its Wnaspi32.dll in C:\Program Files\Ahead\Nero as in XP!).
Next, recall that in the recent thread
LiteOnGuy and banzibaby didn't have any problems with ASPI 4.60, in contrast with your report. Further, within the last six months, I've not seen any reports about users needing NeroASPI under 98x.
I guess NeroASPI is a remnant from the old days where programs coming with various devices (burners, scanners, etc.) tended to replace the original Win9x ASPI with their own ASPI layers, which were frequently either buggy or incompatible with other versions, and Ahead tried to fix the resulting problems for Nero by distributing NeroASPI.
Anyway, if your current configuration seems to be working, there is no need to change ASPI. Note that NeroASPI's version of Wnaspi32.dll calls NeroAPIX.vxd, so I'm not sure if it could be replaced by a newer version as suggested by dodecahedron, especially because the newer versions seem to be intended for NT/W2K/XP only.
I still feel that your ASPI problems could be due to some unique features of your system, such as Backpack drivers.