I have helped 3 people out so far with exactly the same 3 issues when setting up TM1 10 so I wanted to take time to document them:
Tip #1
You are best adding the following parameters to your TM1 10 cfg file if not there already:
AllowSeparateNandCRules=T
DistributedPlanningOutputDir=tunit
The first parameters is because of the new wizard functionality in modeller that helps rule creation and it needs this parameter set to help you write C: level rules.
The second parameter is a new one to do with Cognos Insight and the below explains it:
#DistributedPlanningOutputDir
# Type: Optional, Static
# Cognos Insight distributed clients need information called "tunits".
# This data is created when an application is deployed and is updated as the TM1 server runs.
# The location of the directory used for this purpose is set using this parameter.
# In order to deploy Cognos Insight distributed client applications using this database, uncomment or add this parameter as DistributedPlanningOutputDir=<location of the tunit directory>.
# The pathname specified can be absolute, or relative to the TM1 server data directory.
#
# Examples:
# DistributedPlanningOutputDir=tunit
creates a directory "tunit" under the TM1 server data directory
# DistributedPlanningOutputDir=..\tunit
creates a directory "tunit" as a sibling to the TM1 server data directory
# DistributedPlanningOutputDir=C:\Program Files\IBM\cognos\tm1\samples\tm1\GO_New_Stores\tunit
creates a directory "tunit" at the specified location.
#DistributedPlanningOutputDir=.\tunit