You can just pay for your Will drafting la.

Executor usually most people appoint same as beneficiary.

Then your beneficiary/ executor can go to any experience lawyer to file the court papers for Grant of Probate. Usually lump sum ard 5K.

Caveat Emptor. There are a LOT of useless lawyers. Just like doctors.

Depends on the list of assets/ properties and whether the are local or overseas.

Can ask benzxzx since he is answering questions here pro bono publico

If your Will is simple - everything goes to beneficiary A and if A doesn't survive you, then everything goes to beneficiary B -
then can DIY using a standard template FOC.

Get 2 witnesses with the following criterias
1. Msian citizen
2. Above 18
3. Sound mind and body - eg. employed somewhere is good enough
4. Easily contactable - in case your Will is challenged im court
5. Nothing else related to your Will - cannot be beneficiary, executor etc.