You can make the first investment via RSP minimum investment amount, but that can only be done on 15th of every month

After speaking to a lady with a sexy voice from FSM, this is how the process go :
1) withdraw fund from Public Mutual Berhad and keep the receipt
2) email the receipt to FSM. they would reply within 1-2 days (depending on what time they receive said email)
3) wait for a reply from FSM. Once they have acknowledged, can purchase any fund from the ones listed in FSM for 0% SC except for AFFIN HWANG. (I don't know why is this). When you have  purchased  and transacted, send them an email to remind them to manually adjust the transaction so that there won't be any SC. If say you withdraw RM10K fund from PMB, you have up to 1 month to buy up to RM10K worth of fund from FSM.

You don't have to invest the exact amount. If you invest less, you don't fully make use of your 0% SC benefit. If you invest more, pay the additional with normal SC. Right ?

Yes.

Yes, however, you are advised not to do that unless emergency as the money which is less than a year in the fund will be charged a redemption fee of 1% upon withdrawal