[saurabh_math]

Sure,

1) "I have spent a good while" : here I think you missed "time"

I thought there were more when I was reading it for the first time, did you make any changes? Anyways it looks all correct now :)

P.S. I will add more here if I find anything.

[Igglyboo]

"I have spent a good while" is fine, might sound odd to a non-native speaker however. "while" implies "time" in this context.

[saurabh_math]

Okay, you are right does make sense now.

[jbrooksuk]

"I have spent a good while" is actually ok here.