When you marry then getting a dependent DTV will be easy. Not sure if you mention now wanting to get married it will help as it may look like you want the DTV to just be with your fiancé. If you are marrying soon, consider the METV 6 mths multi entry visa but with correct timed extensions gives you around 8 mths. After marriage apply as DTV dependent.
Yes, especially for Workcation applications they want to see evidence of repeated monthly income to confirm you are employed. Many embassies do approve though for recent employees with no recurring income. There is flexibility, just detail the reason why in a letter.
Anonymous participant if you have wise and a QR Code app like True you will be fine, you have access to many payment forms. Revolut is another multi currency account like wise