cold start: live with it, all rb20det's i have being in owned needed a little prod of accelerator to start when starting them cold.
also in terms of ur performance, remember ur car is all wheel drive, there is much more driveline loss cos ur little engine has to send power to all four wheels pretty much. THere will be much more friction loss etc, hence poorer performance. IN fact HPI found out that a r32 gts4 is about almost a second slower then r32 gtst! And having driven an auto gts4 then straight into a auto gtst, the difference is noticable.