New Owner - couple of minor issues

[markren2004]

2004 1.6 16v Dynamique 30k miles.
got it from auction, so no warranty.
Ive done my own general car servicing for the last 15 years, so not unfamiliar with a spanner.

couple of issues.
1. Steering, when at low speed or stopped, turning the wheel quarter turn back and forth gives a slight clunk best described as a "twang" sound.

2. get message "replace keycard battery", changed the battery and the message still shows on startup 20% of the time. fault with reader or card ? only have one keycard so don't want that to go belly up.

One final question, the haynes manual has the service interval for the cambelt at 36,000 miles as a precaution. Are renault changing them earlier than the service book 72k ? is there much evidence of these failing early ?
thanks in advance.