I declined an offer from Queens last year but want to re apply to them this year

Basically, I applied to 5 unis last year and got 5 offers. One of them was Queens. At the time I didn't want to go so declined and picked another 2 as my firm and insurance. However, in August I got a grade below what they were asking for and did not get into my firm. I'm doing another a level so I can get a better grade. However, after having a great summer in Belfast, I've decided I want to go to uni here but I don't think Queens will want me since I declined them last year. Advice?

Also, can I use my old personal statement? I'll amend little bits of it, explaining what I'm going to do with this year et but I want to keep it basically 90% the same. Is that allowed?

One more question...I'm studying at a further and higher education institution in my city. Do I apply through ucas independently or with them? Because last year I did it with my school. There are tutors at this place but they won't get round to doing anything with us quickly and I want to send my application off school. What is an advisable time to send my application off?

Thanks for the help and sorry for all the questions!