Hi, thanks for that.
It is usual for a landlord to pay for the check-in and the tenant to pay for the check-out (although the latter obligation is only binding on the tenant if he has expressly agreed to it). Additional fees to be present at the check-out meeting are unusual.
If such fees are being sought, a complaint can be made to the agent, stating that it is custom and good practice for the tenant to be in attendance without additional charge and, if the tenant is paying for the check-out, he should be entitled to attend. They can also be advised that the requirement for additional "attendance" fees may be reported to any trade association of which they are a member of (usually ARLA or NAEA) and/or Trading Standards.
Moreover, in November last year the Committee of Advertising Practice (CAP) set out guidance on providing upfront information on letting agents' fees. Even though this guidance (and the decision that instigated it) came after your tenancy, the letting agent could be advised that a complaint may be made to the Advertising Standards Agency if they are not making check-out and other related fees clear upfront.
From a practical point, review the check-in report and take your own date stamped photos of any relevant items or issues before leaving. Also keep a copy of your correspondence with the landlord regarding the attendance fee. These could all be helpful in any later dispute regarding the deposit. The landlord is legally required to put your deposit in a scheme and there are potential penalties for him failing to do this or failing to provide you with information relating to the relevant scheme.
With regard to disrepair, any valid claims can certainly be used a leverage. The landlord is legally required to deal in a timely manner with disrepair to heating, hot water and electricity and a tenant can be entitled to compensation if he fails to do so. If you’re are still worried about your home being unsafe, you should also contact your local council’s housing department. Your council must ensure that home owners and landlords repair any hazards that could cause you harm.
I hope that's helpful.