The self-certifying for ATPL comes in when you have 1500 PIC on multicrew aeroplanes and an ICAO ATPL, but there are variations.
Brexit won't affect anything (if indeed it happens at all) because we are still going to be in EASA.
Your theory exams are valid for 7 years as mentioned above, but fresh out of the exams without an IR, the IR bit runs out after 36 months.
Last edited by paco; 28th Aug 2017 at 06:01.