(1) to be issued (sealed) by the court, 2-3 days will do, now court very canggih, got e-filling system.

(2) 2 attempts for personal service must be made before an application for substituted service will be allowed by the court - as per practice direction issued.

(3) usually is done another way round, defendant engage lawyer, defendant lawyer tell plaintiff lawyer that the firm is acting for the defendant. Once the plaintiff is notified that the defendant has appointed a lawyer, they will serve all cause paper to the defendant lawyer directly, wont send to defendant anymore.

(4) generally speaking, it is not necessary for the plaintiff lawyer to send to the defendant which is residing in Singapore. They only need to serve on last known address or the address as per any contract signed between them. In the event they really have to serve it in singapore, they will need to make separate application to serve it to singapore. In that case, plaintiff lawyer will send a "Notice of Writ". It will be sent according to the rules of Singapore. Not too sure what is the rule for service of document in Singapore... 

(5) Yes they can appoint one lawyer. Yes, sign the document called "retainer letter/agreement" then done. Yes, all correspondence go through lawyer.