Last few playthroughs, I used the Javelin smithing to make millions. So far this playthrough I haven't needed to (smart trading, looting, and selling elite prisoners) bringing me to 300k or 400k. Daily expenses run 1200 (less than 1.5k) and generally each day's activities will bring in at least that much (unless waiting or in an army, which will be a net loss of may 4 - 5k after 4 days).
I also don't fully upgrade all troops unless I absolutely have to, or I have a castle where I can start hoarding Vlandian Sergeants & Banner-Knights, etc. Don't recruit companions until you can easily afford it. Start with just 1. Then wait until you have earned at least 25k before recruiting more.
Invest in some workshops and have some companions or family members lead parties.
I am sure this still applies to higher difficulties.
Re: Daily payments
I don't really have any complaints about it. I do hope in future, there will be a 'Financial report' / overview like in bannerlord for each week or something that the player can view.