Yes - all the steps except for step 6 can be done without any negative impact to ePO. Step 6 is unncessary if the SQL Instance is dedicated for ePO use - since Full Text catalog is not used by it. Your observation on step 2 is also correct. It can be done after moving to ePO 4.5.
Thanks for the reply. After I upgrade to EPO 4.5 does it matter in which order I change the database compatabilty to SQL 2005? Should the system databases (master, model) be done first? Should the steps above be completed again once I change the compatability settings?
Compatibilty mode change is only needed for ePO database- not the system databases. Also, no steps need to be repeated after changing compatibility mode.