I want to practice creating packages for the AppExchange. How do I get access to Environment Hub?

https://developer.salesforce.com/docs/atlas.en-us.packagingGuide.meta/packagingGuide/packaging_testing_signup.htm

this page above points me to "Join the Salesforce Partner Community", but I don't yet understand WHAT is the "Parner Community" / "Partner Program" ? What does that term mean?

The form there asks me several things that don't apply to me:

1) the form there doesn't allow me to use my email (@gmail.com)
2) my country isn't listed
3) it asks for my organization and employees, which I don't have
4) website, which I don't have

Is it possible, and how, to group or nest pages in community using slashes? Adding a new page inCommunity Builder doesn't allow slashes in URL. Does that mean that URLs like /s/segment1/segment2 are impossible to have in community?

How do I set up breadcrumbs to work in Community? I have a number of pages that I want to arrange hierarchically so that they can be displayed in a Breadcrumbs component as a path. The documentation on this is very poor.  When I drag Breadcrumbs component to a page it says "We can't load the Breadcrumbs component because it's not supported by any data. Once you add data, reload Community Builder to see your component."
How to add that data? I have tried to add relative links to pages under Administration > Pages > Site.com Studio > Sitemap, but that didn't seem to affect the Breadcrumbs component. (also, what are the relative links: /s/pageurl or /pageurl ?)

I have an image file uploaded in the community builder.
How do I render an <img> tag with the src attibute of this asset file (and not a Static Resource)?
I would like to do it in markup in an HTML Editor component.

I remember being able to use some expression like {!$AssetFile.asset_name.1}, but not the exact syntax, and I can't find documentation online about referencing asset files.

I have a Task that shows up in Calendar in Lightning experience. Drag and drop for calendar is enabled.
When I click on and drag it to a different day it often doesn't save it. I have calendar display in Week layout. Only in a few attempts did the task date update correctly. It often disappears from the calendar and after refreshing the calendar I find it was saved for the wrong date, sometimes in the wrong week.

Why is this not working and when will it work?

I have an approval process that sends email with a link to the approval page using: {!ApprovalRequest.External_URL} 

Approval page on this link looks very ugly. It just lists the fields and has comment box and Approve/Reject buttons. Is there a way to customize how it looks (html, css) or to replace it with a custom VF page? Where is that page anyway?

I have used My Domain option to be able to use lighnting component on my org's page, but after 1 day of waiting, the My Domain page still says "Registering your domain. You'll receive an email when it's ready for testing."
How to contact Salesforce support for help? When I try to log in on help.salesforce.com it redirects me back to login page.

Thir trailhead (Collaborative Forecasts Configuration / Create Forecasting Reports) instructs me to select "Forecasting Items" as a Primary object, but this item isn't listed??

1. From Setup, enter Report Types in the Quick Find box and select Report Types.
2. Click Continue, and then click New Custom Report Type.
3. For Primary Object, select Forecasting Items

I have used My Domain option to be able to use lighnting component on my org's page, but after 1 day of waiting, the My Domain page still says "Registering your domain. You'll receive an email when it's ready for testing."
How to contact Salesforce support for help? When I try to log in on help.salesforce.com it redirects me back to login page.

Thir trailhead (Collaborative Forecasts Configuration / Create Forecasting Reports) instructs me to select "Forecasting Items" as a Primary object, but this item isn't listed??

1. From Setup, enter Report Types in the Quick Find box and select Report Types.
2. Click Continue, and then click New Custom Report Type.
3. For Primary Object, select Forecasting Items

When I add a new sandbox org, the Environment Hub includes an entry for me to login to this sandbox, but SSO (Single Sign-On) is not enabled. I want to enable SSO on each sandbox org so I don't have to remember passwords for each org and don't want to set the passwords for my user on each org to be the same as this is less secure.

How can I get SSO enabled on all sandbox orgs as/when they are added to the Environment Hub ?

Hey,

In VisualForce you can specify a HTML5 data attribute by adding a html tag to the front - e.g.
<apex:input html-data-attribute-name="some data"/>

We are looking at trying a lightning implementation, but similar functionality is cruitial if we are to proceed.  Is there a way to append a HTML5 data attribute to a lightning component - e.g.
<ui:inputText data-attribute-name="some data"/>

Cheers!