Are my GCSEs enough for Oxford?

Your GCSEs look fine. Have a look at this report, and go down to the chart of outcome by GCSE 9/8 grades. You are in the 10 bar, which is perfectly acceptable, but of course 11 has the highest odds.
Oxford do not care about your personal statement, so I'm afraid you won't get to show off your essay writing. However, they care a lot about your PAT score, so focus on that.

hey!! im in year 12 currently, studying maths, further maths, physics and history, and i'd like to apply to oxford this year, if my predicted grades are enough. but right now i just have my gcses. i have 4 9s, 1 7 [in physics - i wasn't very interested in physics, and didn't like it much until half way through exam season] and 6 8s. i'd like to apply to oxford engineering, which i know is very competitive. i'm very good at essay writing, so i don't think i'll have too much problem with a good personal statement, the interview (if i get one) is one of my worries, but i'll think about that later.
my grades right now, are looking like A*AA [we haven't been tested on further maths content, so i don't have a grade or even a guess for it). obviously, i'm looking to improve.
could anyone give me an idea about whether i'd even be considered for an interview. also i go to an okay-to-pretty high achieving school. most people get 6s,7s and 8s, and small portion get 9s.

You're studying A-Level Further Maths and that will make the first year content a 'breeze' as most of it is A-Level Further Maths Pure and Mechanics content.
You will need to practice a lot for the PAT and start in the summer this year. 😉

Hey - I would say that your GCSE's are absolutely fine!! I received an offer for history with 6 9's, 3 8's, 1 7 and a 5 - though it is for a humanity subject they were very heavily weighted due to the lack of entrance exam. Contextually I fared pretty much the same as you. Though engineering is very competitive I would say (assuming there is one) to make sure you focus especially on the entrance exam. Your y12 predicted grades will also help you stand out and give you a better chance - good luck!!