While I personally hate it and never take it, my personal recommendation is while you are learning the game, always take the national bank idea as your first idea and mint 10% of your income each month. Learning to live within your end-of-year census tax budget and still be effective is one of the most important and (in my opinion) most difficult things for new players to master - having that extra 10% of your monthly income can make all the difference while you are learning the ropes. Once you've got things down, I consider the extra 10% invested in your tech research to be far more valuable then having it in your budget, which is why I don't use it, but that's me - a lot of folks feel differently.
Budgeting with a small, non-CoT country in EUIII can be unforgiving, but very rewarding once you find your proper balance - and make no mistake, Bavaria is a small country in these terms (though for a non-trading power, its actually relatively wealth for a minor - not rich by any means, but there are many countries in worse shape).
Another point - I understand you were trying to get funds to pay back your loans, but disbanding your forces is a poor long-term economic decision. Its going to cost you more to rebuild them then it would have to maintain them at minimum levels unless you take 20 years to pay back your loans - and if you can't manage to pay back your loans in 20 years, you are probably @$%$ed anyways. Not to mention the fact that you are defenseless in the meantime.
Its important to balance your force levels with your budget as a minor. You can't afford to field the 30k doomstacks that someone like France sends running around and won't be able to for some time. But you should be hitting other minors with one or two provinces and avoiding the big-boys until you've grown a bit anyways - you don't NEED 30k stacks or even 10k stacks. When Anhalt is running 3k, send 4 or 5 with a decent general - its all your need and far easier on the budget.
Trading is very useful for maintaining a solid tech lead or at least holding even with your rivals. But don't look at it to fund your military - it will actually take money away from your yearly census funds (it costs to send merchants) not add to it unless you are minting. Its still a valuable investment, and every country should be trading at least a little. If you aren't trading focused and find you can't keep merchants in the high value CoTs, either go merchantile and stick to owned CoTs (once you own one or more) or stick to several lower value CoTs where the competition isn't as high, even if the rewards are lower as well. But its still to just ignore a third of your potential investment income.
Budgeting with a small, non-CoT country in EUIII can be unforgiving, but very rewarding once you find your proper balance - and make no mistake, Bavaria is a small country in these terms (though for a non-trading power, its actually relatively wealth for a minor - not rich by any means, but there are many countries in worse shape).
Another point - I understand you were trying to get funds to pay back your loans, but disbanding your forces is a poor long-term economic decision. Its going to cost you more to rebuild them then it would have to maintain them at minimum levels unless you take 20 years to pay back your loans - and if you can't manage to pay back your loans in 20 years, you are probably @$%$ed anyways. Not to mention the fact that you are defenseless in the meantime.
Its important to balance your force levels with your budget as a minor. You can't afford to field the 30k doomstacks that someone like France sends running around and won't be able to for some time. But you should be hitting other minors with one or two provinces and avoiding the big-boys until you've grown a bit anyways - you don't NEED 30k stacks or even 10k stacks. When Anhalt is running 3k, send 4 or 5 with a decent general - its all your need and far easier on the budget.
Trading is very useful for maintaining a solid tech lead or at least holding even with your rivals. But don't look at it to fund your military - it will actually take money away from your yearly census funds (it costs to send merchants) not add to it unless you are minting. Its still a valuable investment, and every country should be trading at least a little. If you aren't trading focused and find you can't keep merchants in the high value CoTs, either go merchantile and stick to owned CoTs (once you own one or more) or stick to several lower value CoTs where the competition isn't as high, even if the rewards are lower as well. But its still to just ignore a third of your potential investment income.