ICA - LTVP foreign spouse documents and extension of stay

1. You can keep ready your foreign job details including salary part ready if ICA asks then you may submit. Or else if you are transferring a cumulative cash to here then show your local bank account. Otherwise your spouse’s financial situation can only benefits as she or he has to declare it to ICA. If you got a job here before marriage then your salary pay slip would matter. Both of your monthly salary or income should be at least $4k to $5k.

2. On Translator of your certificates, you can liaise with many local translators here such as:

Wordsburg.com.sg
lexigo.com
awardtranslation.com
translators.com.sg

These can be done in few days, so once you arrive then engage with them. Your spouse can initiate to discuss with them in adv, if you want.

3. You have few options such as get a job after you came here and get EP or S pass for that. So, you don’t need any LTVP.
In general, your STVP will be for 30 days and can be extended to another 30 days. You may both plan for marriage then apply LTVP in first two weeks of your arrival and subsequently apply for STVP extension.

ICA does not approve or recommend any translators.
But your country's embassy in Singapore can probably give you a list of translators they use and recommend.
Certified translations do not expire (unless the content of the original document does not change).

"I currently have a job in my home country, and I was wondering if the financial information required by ICA such as foreign spouse's monthly salary and  payslips for the past 6 months would apply for me since I'd have to provide that information based on my current home country's job salary and payslips. I think this is probably for foreigners already working in Singapore, but I wanted to confirm that."

Correct. It's only for foreigners already working in Singapore. That's why each of the questions about spouses current job and earnings includes the words "if applicable".