1) if your account is with Maybank then select Maybank
if your account is those account with Maybank Islamic then select Maybank Islamic

2) Stashaway Simple is MYR Money Market Fund portfolio, so no currency exchange involved, there no conversion fee
conversion fee only happen when you deposit money into your Stashaway foreign currency portfolio, since your MYR is converted into USD
and also happen when u sell/withdraw, because Stashaway convert your USD back to MYR to deposit into your bank

3) refer (2)

There's two approach to this really.

2. Be flexible post end-of-income
Be optimistic that the market will spend more time being great and less time being trash within my lifetime, and adjust my living standards according to market performance - 90% Equities, 10% Bond (SRI 8%)
Always withdraw only 3.5% per year of current holdings - if its an amazing year, the 3.5% will be bigger, and I can spend more on luxury stuff that year - if the big bad event happen, and I lost 50% of my value over night, then no choice, just have to live on nasi lemak and bread or whatever I can afford with the 3.5% of the 50% left.

a well balanced ETF will always go up in the long run (e.g., 8 good years, 2 bad years) so if you turned a profit, you should let profits run. cashing out fully is a form of "timing the market", so just cash out some and leave behind whatever amount you are comfortable with

I'm terrible at explaining things, so I may mangle some concept and terms... as this is getting closer to financial planning territory - do not take my answer as financial advice, seriously, I don't know shit, if I am well off I won't be sitting in lowyat forums.

You'll have to look into the further details yourself, but the gist of it is, after a certain point of investing, your yearly profits from investment alone can sustain your spending needs without any further income. FIRE's idea is to bring that earlier than retirement age.
3-7% are common withdrawal rate that people choose - i.e. If you have a 2million portfolio, you can spend up to RM5k a month and still have your portfolio grow with 0 additional investment and traditional income.
The higher the withdrawal rates are, the more likely your portfolio cannot sustain you until the end of your life due to economic turmoils or other reasons.

So, for your first question, 3.5% is the number I've decided for now as my target safe withdrawal rate. Does that make sense?

Coincidentally - this is also why fees are VERY important. You may imagine the impact of paying SA 0.8% a year when you are sitting at ~3.5% withdrawal rate. This is why partially why SA consist of only 40% or less of my total portfolio as VWRA's fees are only 0.22% a year and have a good chance of going lower.
As for your follow up questions:
I very much agree with that. If you lock it in, your money stops working for you - now they are sitting around getting eroded by inflation and subjected to currency risk - instead of "whether they will run out" - it became a "when it will run out" issue.

It's more likely that you will simply stop depositing when your income stream stops and just let your money grow by itself.

I don't own individual stocks,  but the mentality only applies to SA & VWRA which makes up 90%+ of my portfolio. I don't particularly differentiate growth and dividend stock either...