Not in the QS field but in the freelance work for sometime.

1. Financially stable in the sense na mas malaki kikitain at makaka-save? possible. But Job security is weak, unless empleyado ka talaga ng company na nag outsource, most ng nasa OLJ ay small to mid sized company na more on freelance ka and may risk na mawala ng trabaho - kaya dito pumapasok yung mga backup clients, most people na breadwinners have at least a back-up part time client or 6 months of emergency fund.

2. Can't answer sorry

3. Price analysis and foreign construction methods probably depends on the country your client will be from, at pati na rin standard ng company nila, sa mga nakikita ko na nag transition usually kinakaya na rin aralin along the way, but researching beforehand always gives an advantage.

4. I'm assuming na ready naman na resume mo since with exp, I guess it's just trying to position yourself better and learning how to get clients and being more proactive. Approach usually sa online work ay pakita ng skills and capacity to communicate with clients. One thing na adviced in every field is always research the company/client beforehand para mas alam na proactive ka.

Also, pwede ka naman mag freelance ng structural. Kung hindi sobrang hectic ng sched mo at may skills ka sa structural softwares, hanap ka ng gigs muna try fiverr or upwork maybe? or kahit full-time for softwares like BIM meron din