It is good that you are able to walk independently. Regarding your questions. It is not advisable to bend your hip more than 90 degrees; you should particularly avoid bending and rotating your hip inwards. Generally there is no problem in having sex. Half replacement (hemirel) hips tolerate wider range of movement i.e. they are more stable compared to total hip replacements. Life of implants generally depends on patients activity level and a younger, more active patient may require revision at an early stage. Usually primary arthroplasty lasts for about 12-15 years.