Sometimes he made ... and other times ...

I'd say

Sometimes he made the euergesiai in the form of a gift and in other times in the form of a loan.

Richtig?

"in other times" has a different meaning than simply "other times" or "at other times." I don't think you mean the "in" version. "In" make the times sound more epic: in times of drought, in times of war, etc.

Ich habe mich verschrieben, danke.

Dude's #1 is fine (it shows another good option), but the OP formulation is also fine.

# 5 the OP formulation is also fine.
I don't think that's true, but I think this version would work:

Sometimes he made the euergesiai in the form of a gift, sometimes in the form of a loan.

Alternatively, leaving out "he" may make it flow a little more smoothly:

Sometimes the euergesiai was in the form of a gift, sometimes/other times in the form of a loan.
Sometimes the euergesiai was in the form of a gift, sometimes/other times it was a loan.*

* I don't think that repeating "in the form of" improves the style; if anything, the opposite is true.

I don't think it does any harm.

Hi, Captain.

I think you have done a service by showing some (very good) options. But I see nothing wrong with the OP version.

I'm obviously not the captain, but I didn't like the placement of the OP's first "sometimes." It seems a bit "unnatural" (or stilted?) to me.

To me, the OP version is smoother (for want of a better word) and somehow more satisfying (and maybe less "programmed"--again for lack of a better word).

There's nothing wrong with either, but I somewhat prefer the OP. It's a matter of personal preference. (I might also still be under the effects of Thanksgiving dinner.)

I'm not too keen on the OP version, though I would probably regard it as acceptable.

To me it is different from the version in #2 in that (as I read it) it uses the set construction "sometimes ... sometimes" (mal ... mal), which makes it OK (and less restricted to temporal contexts) but slightly awkward when used as an integral part of the sentence.

If it is initially parsed as two separate occurrences of the temporal "sometimes" it sounds about as unacceptable as: "He made the euergesiai sometimes.". I think this is the root of the problem.

zu #6: Sometimes the euergesiai was in the form of a gift

Es sollte "were" heißen, denn das Subjekt steht im Plural:
euergesia: a good deed; Original Word: εὐεργεσία, ἡ (f. Sg.)

#12 I have no Greek, so thank you for pointing that out.