1. How long did it take for a transaction to be confirmed?
Transactions before were so quick that it won't take 2 minutes IIRC and I was able to catch up those days that there's no fee when you send bitcoin. It is because there were few users unlike today.
2. What were the other issues experienced apart from Hardware complications and energy requirements?
Can't say on this matter but before the earliest time, you can mine even with your laptop.
After reading this answer, before the transcation is very quick and no fee because not many user but low price.
So now many users, all crowded and high fee but good price. So what do you choose now? I think its difficult decision.