Verb woes; two or three questions

Question

I'm working on a translation and there's this one line I can get through but can't get a handle on.

こんなヤツに負けおって いままで何のために練習 してきたと思っておる!

• Problem 1 is that I can't figure out if this is one sentence or two sentences respectively ending on おって and おる.
• Problem 2 follows if these are two sentences: what would the -て ending mean here? An answer to another question mentioned that the -て ending can mean that the line of thought hasn't ended yet and that's the only thing that seems to make sense.
• Problem 3 is 何のために, because I can't make "for what" work. I've been
  wondering if it could translate as "for nothing" ("To think that all this time [=until now] you've been training for nothing." But I worry I'm making a mistake.

The context is a very angry coach raging at their star pupil for losing a crucial match.

Thanks in advance!

Answer 1

こんなヤツに負けおって いままで何のために練習してきたと思っておる！

1. I would read it as two sentences, respectively ending with おって and おる.
   I think it's also possible to read it as one sentence, though.

2. You can think of the て as indicating 非難 (reproach) or 不満 (complaint). For examples: https://japanese.stackexchange.com/a/51775/9831
   When you read it as one sentence, I think it'd also be possible to interpret the て as indicating a reason or cause for the speaker to utter 「今まで何のために～～！」

3. 何のために means "for what". The sentence is interrogative.
   何のために練習してきた？ "What have you been training for?"
   何のために練習してきたと思っておる？ "What do you think you've been training for?"

Answer 2

You’re right. The coach thinks the player wants the other team to win since he is not performing as he should. If he was, they would be winning. So, I feel that the coach is saying, rather rhetorically in anger,

“Are you trying to tell me lets lose the game to those scumbags?” Or “Are you telling me let’s lose to those guys?!”

“I can’t help but think what have we been working so hard for all this time?!”

という感じはします。