I would like to address some of your original points, hopefully it will be helpful:
First, not sure how familiar you are with the Mobile Access policy model. Back in R77.x the Mobile Access policy was defined in the SmartDashboard on its own dedicated Mobile Access tab.
In R80.10 we introduced the option to define the policy in the Unified Access Policy, this is the Unified Policy option. One can still define this in the previous way, in the Smart Dashboard, which is the default and referred to as the Legacy Policy.
As you noticed, you can toggle with the Policy Source option to choose which the Mobile Access policy will be used.
* Policy verification error “R80.10 gateway cannot be included in the Mobile Access Legacy Policy when Mobile Access unified Policy is the selected policy source”:
As mentioned, this is indeed a known bug, which was resolved in R80.10 Jumbo take 70.
The greyed-out checkboxes for Portal URL and SSL Network Extender: this is by design, but I agree the UX around it can be improved to not confuse users that this is a bug, we will see what can be done.
* Policy verification error “The Mobile Access Policy does not contain any rules”:
This is an expected error if the policy source is the Legacy Policy and indeed it contains no rules. If I understand correctly, you configured your policy source to the Unified Policy when this was encountered, in this case this should not be shown. We will double check this in our labs. But if you were on the Legacy Policy, make sure to have at least one rule defined, otherwise Mobile Access has nothing to enforce, hence the error.
* SNX did not connect, before and after installing the deployment agent HF, in neither browsers: Now, this is strange, because it was thoroughly covered in our labs and we know concrete customers that have this working. We have doubled-checking this and it works flawlessly in our labs. It could be a misconfiguration. I would suggest seeing which IP is defined on the gateway object in Smart Console, and if it is a routable and main IP you intended. The SNX client will attempt to connect to this IP, if it is not routable, one can expect the SNX client to endlessly try to reach it. In addition, I would also suggest to try and remove the SNX installation (from the Add/Remove Programs) and try to reinstall it by browsing to the portal after it is uninstalled.
In any case, I do agree that in such a case we have room for improvement in the UX around notifying the user on such as case.
* Firefox and Chrome compatibility – In order to use SNX from the SSLVPN portal, via Firefox and Chrome, one indeed must install the Mobile Access Deployment Agent HF.
Due to the scope of functionality introduced in this HF, it was not yet integrated to the Jumbo releases, we have concrete plans for this, but it will take a bit more time.
* Web applications are not published in the SSLVPN portal: The way it works is, that the portal will show only applications the logged in user is authorized to. This means that after you defined the web application, you need to define a rule in the Mobile Access policy, which allows the application to the user.
In the Legacy Policy, navigate to the Policy tab and place a rule with a user group containing the intended user, and then in the same rule place the intended we application you want to publish for that user.
If you choose to use the Unified Policy, this is similar, just used an Access Role object (instead of a plan user group) as the source and place the application in the Applications column.
* If you still have any questions or if things are not working as expected, I strongly suggest to engage with our excellent Technical Assistance Center, who can guide you through your obstacles.