For local events, there's no problem with removing the baby teeth. Hang on to them in case you get competitive and want to run a money event someday.
Similarly, there's no problem with the oil filter relocation locally. Just make sure it doesn't leak. Pay close attention to where the lines run so that they don't cut through your a/c lines (or, eeek, vice versa).
Welcome to the forums! Come on out to any autocross! We can probably get you a ride along at any event, but you can get the most "instructor" time at S2K, ER or PCA events. Even though fewer of us show up for PCA, you'll still have your choice of excellent instructors.