Now that you've kindly sorted the Acrosses for me thank you, here are the Downs (it's obvious when it's pointed out isn't it!).
1d Where you'll see Victoria and Mike bathe (4) - SWIM?
18d Quickly perform rhythmic monologue without real committment? (7) RAPIDLY?
30d Ceramic business set up by American organisation with influence (7) OCTOPUS (I can see OC and US!)
49d Yoghurt concoction and Italian sorbet, neither good nor new (5) RAITA
No doubt these will all be obvious too!