Try it with clean config files. (remove everything and use only the original config files from Sitecore)
If there are tools like synthesis, for example they can regenerate the model over and over again and slow done the installation.
For the upload:
1) Check the web.config on upload limits, httpRuntime maxRequestLength and the <security>
2) Check the <processors>
<uiUpload> in the config (you can do it with the url /sitecore/admin/showconfig.aspx on CM, are there custom processors?
3) check the log maybe there is somethings that explain.
Check the log file will installing the package there you can see the progress.