We stayed in Lindos and were at the back of the village, there were quite a few steps, and not very good ones at that. to the beach was more or a climb but not steps. You could get the donkey up from the sunburnt arms beach. There are some properties that do not involve steps
Lindos is a lovely place

within Lindos it was mainly very steep inclines. However, you may have to watch your accomodation. Ours had quite a lot of steps taking it onto the road. Re the beach- I can't remember to be honest if there were steps or if it was just a slope- but if all else fails you can use the donkeys!
Seriously, the slopes can be hard going and my calf muscles were agony for the first few days. Absolutely stunning place though.

Lindos is very hilly so steps can be a problem at some properties but not all. The closer you are to the centre the less likely there are to be steps to your accommodation but get your travel agent to check for you, many with lots of steps list this in the brochure as 'not suitable for people with walking difficulty'. If there's any places in particular you're considering let me know as i know of quite a few so might be able to help.
The centre of Lindos is reasonably ok, the steepest incline is down to the beach but you can visit either beach without using any steps. There's also many steps to the Acropolis and although you can take a donkey to the main gate there are more steps inside so that's one probably best avoided.
The restaurants are well know for the roof garden restaurants which obviously involve steps but nearly all have a seating area at ground level too.