One important thing I should say:
Replacing *STRT-MEM-SHORT by *MEMORY and *STARTUP-SHORT may not be the best idea. The reason is the following: the *MEMORY parameter causes avast! to scan the operating memory of the computer (i.e. the true virtual memory). The *STRT-MEM-SHORT scans (besides the startup items) the modules loaded in memory (i.e. the corresponding files, not the real memory).
While the *MEMORY parameter may catch unknown (packed) variants of viruses that may not be detected on disk (they can be found since the packed file is already unpacked to memory), it may also fail to detect the viruses for which only a packed variant exists (and the VPS does not contain a signature for the unpacked code). Generally, avast! virus database is optimized (and checked) for the file detection - the "memory scan" is rather a special additional feature.
So, if you want a real thorough check of the memory/startup, I'd rather recommend using both the parameters *STRT-MEM-SHORT and *MEMORY together (or, *MEMORY, *MEMORY-SHORT and STARTUP for all the user accounts).