Rosemary hates sitting in wet soil or compost - doesn't seem to matter if it gets a lot of water, as long as it drains away quickly. Apart from that it is very tolerant. If it decides it likes you it will live forever, sometimes outgrowing its allotted space. They do say (the "old boys") that Rosemary grows best where a woman wears the trousers, so to speak - don't know whether that has been backed up by research. As for mine, I've two plants grown from cuttings, both doing well but planted on light, free-draining soil, one in sun and one in shade. "They" also say that the best pruners are flower arrangers and cooks, cutting little and often. Having said that I've managed to renovate quite a few old shrubs in my garden by really hard cutting back. Mind you, it always pays to take a few cuttings before resorting to such drastic action.