Most projectors have a quoted bulb life of 2000 - 3000 hours, and many projectors will refuse to start up after the bulb has reached a certain number of hours.
You will want to minimize ambient light for movie watching, but some light is OK for less critical watching. I watch TV on my projector with the lights on in the room. Direct sunlight WILL wash out the picture.
I have a Sony HS10 and have been very happy with it. There a lot of great projectors available for less than $3k. There is a lot of good info at
projectorcentral.com.
