The nearest train station is Salisbury, which is easily accessible from London and other major UK cities. Once you are in Salisbury, the bus station is roughly a 10-15 minute walk from the station. Ask the driver to drop you at the Thickthorne Crossroads and walk from there (follow the Larmer Tree brown signs). A one way taxi fare from Salisbury will cost around £40.
Yes. There are viewing platforms for those with the correct wristbands, and an Accessible Camping area with parking very close by. There are also wheelchair charging stations on site. Access for personal assistants or guide dogs can be arranged by emailing email@example.com.