Can my landlord raise the rent without reason?
On a month-to-month agreement your landlord can raise the rent for any reason and does not have to specify the reason. However, the notice should be in writing. So until it is in writing you do not have to pay the increased amount.
How much can my landlord raise my rent?
Once you are on a month-to-month contract your landlord can raise your rent at any time for any amount s/he chooses. S/he must give you 30-day written notice of any such proposed raises. If increase exceeds 10% of the lowest rent charged within a 12 month period, s/he must give you 60-days notice.
Is it legal for a landlord to raise the rent during a one-year lease, but not give the tenant the option of leaving if this occurs?
No. The terms of a fixed term or one-year lease are “fixed” for the specified period of time.