As per your concerns;
1. I don't think forgetting to write your name at the back of the envelop will have any significant effect on processing of your application, provided the address you wrote is correct. They will still receive the your application parcel. And by the time they open it they will know your name.
2. To the best of my knowledge, I don't think your IELTS expiring date will have anything to do with your processing time again. Since your application is already with them then you are safe. Similar to your Manitoba certificate, you are only advised to send your full application for processing before your provincial nominee certificates expires.
Note: the whole processing can not finish before April (the expiring date of both certificates). You still have a long way to go, e.g. biometric, medical etc.
So stop worrying yourself on these two concerns