when a mana barrier is up would a mundane be able to just walk thru it
Yes. Also awakened that does not currently use astral perception or astral projection or critters that are not dual natured. They would typically not even notice that its there (but note that sustained spells and active foci etc will cause astral intersection)
or would it stop or slow them down, same with and awaken with no sustained spells or foci?
Awakened (in this edition) are not stopped or slowed down by mana barriers, unless they are currently dual natured.
what cyber do you need to have a DNI with your gear?
You get DNI by wearing trodes (no cyber).
Or by having an implanted datajack, cyberjack, control rig, commlink or cyberdeck.
DNI is useful for AR as it may replace need of devices such as earbuds and an image link.
To get "Super AR" where you not only see and hear the matrix, but also feel, smell and taste it, you need a SIM module (using a commlink modded with a SIM module, accessing the matrix via a cyberdeck or by having an implanted control rig).
To enter VR you need both DNI and SIM module.
To jump in you need to be able to access VR but you also need to have an implanted control rig (and the target device need to have a rigger interface and you need to have access on the network the target device is part of). If you use a RCC then you may jump between devices without first jumping out.
