A world of opportunities...
Once you are in the big Green Machine and have your DPM's / MoD 90 / chit in lieu, the world is your filter-feeding mollusc.
Whilst at Uni I spent a year in Germany and did a bit of river crossing with the Bundeswehr in Marders, another guy at LUOTC got his Spanish Para wings whilst away. I also had the mixed pleasure of playing a shot-down Russian pilot during Ex Brave Defender, including a 'Blues Brother' moment courtesy of the Yorkshire Volunteers.
Your TA / OTC unit will have frequent opportunities to 'do stuff', according to how much time you can divert from your studies/wine/women/song (delete according to taste). IIRC, you cannot be comp mobilised in the TA if you are still a student, so your degree is protected.
As per the UAS, there is no RAuxAF presence in NI but 602 Sqn in Glasgow might be prepared to cover your travel costs to and from training. NI has a range of TA units, including a detachment of 23 Intelligence & Security Company, a Battery of Light Guns (Royal Artillery) and of course the Royal Irish Rangers.
If you want to go on exercise with the RAF during your Summer /Winter hols, a polite phone call or letter to the RAF Sqn's Adjutant will open alot of doors. Tell your own Unit Chain of Command first of your intentions and keep them in the loop, you'll most likely get paid for going away too !
Hope this helps.
FP