i think bio unit 1 is essential because it's where you learn about cells and its structure, functions etc. which will definitely help for yr 12 bio. im only doing unit 1 bio this yr for a semester casue the teacher sed unit 2 was unecessary caseu it doesnt really blend in with units 3 4 bio. I personally think bio is a lot more hard work (rote learning) than psych but is way more interesting. It seems you like bio more so do it. However VCE is a one and only chance sorta thing so it may be risky.
i think you should do 7 subjects in case you might regret hadnt doing bio or vice versa, psych. hmms in yr 11, you have more time to spend on your 3 4 subjects but on the other hand, your brain isn't as developed to grasp teh complex concepts as to the competing yr 12s?
im plannign to do the same subjects as you, except normal english and not english language

. im a mathy person and found bio really draining when i had this other teacher in normal science but wen i began doing bio as an individual vce subject i found it fun and interesting! bio usually relates to med too

psych for me is even boringer but thats just my opinion. XD i did accounting unit 2 also, and i found the tables all confusing i prefer problemo solving type of math lol. But it was lucky that i did it or else i would have never known and even pickd it nxt yr! so mayb wen you do bio without 1 2 you mite not like it anymore and itll be too late to change?
anywhoo gd luck though.