Need additional container


I wanted to purchase more containers for my project.But I have the below queries can you please let me know the below details

1.In Linux plan,it shows 1 concurrency for 16 containers.Does it mean I can run 16 builds at same time on different 16 containers or is it 1 build at a time but we can use any of the container
2.What all can we run on Os X plan.Can we run the regular test which run on linux machine in OS X plan along with Apple ios developed apps or we can only run aplle ios apps. have mentioned the build time as 1500 minutes per month .What exactly is the build time for a Linux or Os x plan
4.Build gets timeout after every 2 hours.Can we extend the timeout time to more than 6 hours if we are purchasing any plan.
5.What is the difference between parallelism and concurrency in your plans
6.Can we configure the container size.Heard that max size is 4 GB.If our project requires more GB can it be configured.
7.Wanted to try the free trial version for OS x ,7 concurrency but since I am enrolled to free plan its not allowing me to see how OS x plan works.
8.Can we see the UI flow now we can see only logs