inheriting lease with no end-date?

[Marci Stein]

Put offer on house with tenants in place. just got the lease sent to me to review and it starts in 2008 with NO expiration date....is that acceptable,or does it automatically expire after a year?
Also, lease has incorrect address on it-it says # 97 but it's 128 (correct street, at least). Also, lease states 7 people can live there (its a 2 bedrm).
can i change thta?thanks!