Thanks for your response
You really should list the request for me to check your completion of the SA109 as a new question - as this is over above what your initial question asked for assistance on (this is Just Answer policy) but as this is your first time on Just Answer, I will proceed with providing this support within this question thread
You may not be classed as resident - but you were for 2013/2014 and for the last 3 years - so you may need to recheck that question and also consider how long you plan to stay out of the UK so you can determine your own residency position - although IF you did complete form P85 - then HMRC would have advised you what your status would be. So in the absence of this - you will need to work this out as per RDR1
Link here https://www.gov.uk/government/publications/residence-domicile-and-remittance-basis-rules-uk-tax-liability
Yes you will ask for split year treatment
Yes for 15
No for 16 as you have made the claim for personal allowances at 15
And 18-22 could be relevant for you as you need to who the codes for the other country for which residency would have applied through 2014/2015
And of course you will have an employment page and rentil income (UK property) at the very least
HMRC free online self assessment is not able to support the SA109 as its unable to "read" the implications of the form co,completion and how this transposes to your tax liability.
Tax Calc is a good one but so are all - just make sure they can support the residency and other pages you may need to complete.