Performance tuning of ERP System called axavia

Question

I'm working here in a small company and one of my jobs is the administration of the ERP system 'AXAVIA' (www.axavia.com)

There are .NET Clients and a MSSQL Server 2005 Database with a size of about 10GB. The system works on a metadata model, this means they have very few tables (one for each datatype and some for the relations) and this data is computed with adhoc queries. Up to 2000 batches / sec...

I guess they don't really hava a database specialist, because the didn't know anything about index fragmentation and i allready deleted a lot of unused indexes - now the db is about 30% smaller...

What else can i do for more performance? - I rebuild now the indexes every night

• I think, there are no 'missing indexes' and also the primary keys are at least 'ok'
• The filesystem is a fast 10 raid - and with 6,6 GB Ram there is very little IO
• The Server is a VM Ware with one virtual CPU - here i guess is the beste possibility: The huge ammount of small batches would benefit from a phyical cpu with 4 cores?!
• I'm also thinking about partitioned tables, but in the moment the database isn't big enough to benefit much from this.

So - any other ideas?