All three land in the same place.
Once you have registered, the button reads My registration. That is how you tell at a glance that a conference is one you are going to.

On-site or Online at the top, then Presenter pass or Audience pass below. Everything you see beneath changes with those two.
Two strips above the passes say what is already applied: whether you belong to the host community, and any discount that carries with it.
Members get 15% off every registration type, applied automatically. There is no code to enter.

A presenter pass cannot be bought in advance of a decision. Until a proposal of yours is accepted, the panel shows a notice and a Submit proposal button where the prices would be. After acceptance the notice changes and the prices appear.
Acceptance qualifies you. Registration confirms the place.
Your presentation type decides which registration options you see. It is fixed at submission, so if it is wrong, contact support — it cannot be changed from this page.

Each pass lists its rates in dated windows — usually Early, Regular and Late. One is on sale at a time; the others read Expired or Not on sale yet and keep their prices on show, so you can see what you missed and what is coming.
If you need a letter of invitation for a visa or a funder, register early. It is released by registering, not by acceptance.

Not until presenter registration is complete. Acceptance qualifies you; registration confirms the place.
Presenter passes unlock on acceptance. While a proposal is under review the panel shows a notice instead — an audience pass is available in the meantime.
Check which window is on sale. Early rates close on a fixed date whether or not the conference is full — and the tab you are on, Regular, Student or Local, changes every figure on the page.
Yes — an online audience pass. Registration is what opens the programme, the digital media and the discussion boards.
Register first. Acceptance releases a letter of acceptance; the letter of invitation is issued once registration is complete. Both sit under Download letters and certificates on your My events card.
Yes, with proof. There is an upload step built into registering, and what you upload is reviewed before the rate is granted — it is not applied on the strength of picking the tab.
Contact support. The switch is not something you can make from the Registrations tab.
No. It comes with presenter registration and runs beyond the conference, which is why the panel links to the community it belongs to.