Hi there welcoe to the forum! yes for singapore spouse visa can take anytime to 21months. Yes you can apply for Temporary resident visa aka visitor visa while PR application in process.Theres no maximum amount to show but it depends for how long your husband plan on staying in canada based on that you need to show proofs of money ,shelter to live in canada. Your husband could apply for anytime to 6months maximum. By the way your husband has to apply from bangladesh not you from canada.He has to submit his aplication to VFS in bangladesh, they have office in dhaka,chittagng,sylhet. I dont think the fact your husband lived in australia before gonna make any difference on his application. The most important thing is to show that he has ties in bangladesh otherwise they will believe he is not gonna leave the country after visa expires and thats mostly one of the reason most of application get refused....