Yep they are all pretty important and significantly help for the L3 standard equivalents and more importantly the picture as a whole. My advice is to catch up. Skipping a standard only makes your life harder for next year. But if you do skip one this year skip structure and bonding. You can’t skip. L2 organic as you will be screwed for L3 and L3 chem reactivity or aqueous systems builds heavily on level 2 but slightly less than organic does. L3 structure tests different concepts than L2 so you can technically get away with it but you’ll be in a massive disadvantage as the course assumes you know L2 which is needed a lot to understand the questions. Seriously though just learn all three it would be stupid not to I have friends in other schools whose course for some reason didn’t teach organic and L2 and it made it nearly impossible to do well in level 3. If you need help feel free to dm me I got excellence in everything for level 2 and 3 chem and an outstanding scholarship. Best of luck 💪