MonoX during the installation isn't creating any temporary files, so this access denied is probably an issue with the shared hosting provider setup.
As for web.config write permissions you need to ask hosting provider how to set the write permission to the web.config file because we don't know what software are they using (It is Plesk, Helm or their own).
If you can't set the write permission on the file, or they (hosting provider) do not want to give you a permission to set this on the web.config then you can do it manually.
After the install you need to go to your hosting provider's panel and edit the web.config.
1. Find the '
' and set this to '
2. Find the '
' and set your DB connection string (If you don't know what is this then I suggest you ask the hosting provider to send you an IP address of provided SQL server and the small tutorial on how to setup new user on that SQL server).
I hope this will help you, keep us posted on your progress.