1. Pte Ltd minimally needs 2 shareholders up to a certain number (not sure how many) before it becomes a Limited Co. Structure. If the Company gets sued, any resolution against the Company's favor will be paid out, limited by the company funds. eg if XXX Photo Sch Pte Ltd has $888 in funds, and gets successfully sued for $5000, the company will go into bankruptcy without the directors themselves going into bankruptcy but of course they have to prove their reasonable discharge of duty, etc. Talk to your lawyer for full detail.
2. Pte Ltd needs to do many things, like call for AGM, file Annual Returns, etc. There is a lot of paperwork to keep track of, too. If your revenue exceeds a certain amount you may need to have your accounts audited by a Public Accountant type. meaning must pay $. Ask your lawyer or accountant or read the documentation about the sum.
3. You can already establish your webpage before registering ACRA. Whether you may legally transact business is a grey area though.
Please speak with a professional about this. I find that the Limited Liability Partnership structure most useful as there is protection for partner and also not too much paperwork (but merely declaration of solvency every year)