You can express clear a cheque for the next day i.e if it is paid into the account today it will be credited to your account tomorrow but this service costs extra.
No. Cheques paid in on saturday will show in the account as being credited on monday and takes 5 working days thereafter to clear. Rule of humb - english bank cheques 5 working days, scottish bank cheques - 7 working days and foreign cheques 2-6 weeks
Some banks do a three day cycle. like HSBC. Example: pay in on Wednesday before 3.30pm, your cheque will clear for withdrawal and interest purposes Midnight Friday, therefore being available to take out on Saturday. A chq can never guarantee to be return unpaid - believe it or not. So if you use Ebay, always allow 10 days on a chq just to cover yourself.