Quite an interesting question. First of all, let's translate, shall we?
Translation:
(1) a. If it isn't possible to finish today, I'll also be troubled.
b. If you can't do it today, finish it tomorrow by all means, please.
(2) a. If the weather is fine tomorrow, I want to dry the futon, at least.
b. If the weather is fine tomorrow, why don't we go for a drive?
(3) a. If I had money, I would return my loans.
b. If I had money, I would go around the world.
A brief explanation:
As you can see, all sentences have an "if/in case that" meaning. But, what's the main difference, you ask?
1. When you use ~ば, you can't do it with a noun, or a な-adjective.
2. ~ば is always in present tense, while ~たら isn't bind to that rule.
- You wrote the examples yourself. Look at them ^^
3. In case of ~たら, the first sentence is always before the second.
- If I didn't have money, how would I possibly be able to go around the world?
4. Still, do remember that when you use ~ば、you don't have an act of free will.
- やればいいんだろう? -> It's alright as long as I do it, isn't it? (You forced me to do it)
5. With ~ば, there can't be any requests, commands or linear events.
午後になれば、コーヒーを飲みに行きましょう。: That one is WRONG! (There can't be any linear events)
I'll write the rest in a separate post, since you can't use more than 2000 characters, it seems.