With the clothes. I won't let my bio kids go to school looking like that. But if I suggest SS8 change his outfit and he chooses not to, I have to let it go. Its not worth the mental energy to fight it and there are enough other problems with my stepkids that I do focus on because it actually affects my well-being.
 

It's hard when I drop him off at school and I worry about people judging me as a parent, but I'm not his parent whether they realize it or not, and I'm getting better at not worrying about what strangers think. Maybe try to focus on your own kids more if you have them, and if not, focus on yourself.
 

Pick your battles like the food. I would still let DH handle that, but we say to all our kids, they eat what we give them and we don't make special meals for them. If you are cooking, on your end, don't give into that and go ahead and make what you want to make. If they complain, too bad. If it bothers you, make DH do all the cooking for your stepchild. 
 

Like OP said, you can't care more about the stepkid than bio parents, unless it is something that negatively impacts you. It's hard to bite our tongues but helps to have an outlet like this to vent.

This is a control issue.  They are controlling you.   NO.  You make what you want either they eat it or DH deals with it 

Clothing style. Not my hill to die on as long as it is school appropriate. When it doesn't meet the dress code, and they insist on wearing it after reminding them that it dies not meet the dress code, their dad can deal with the call from the school to bring them something appropriate.

Too small clothing disappears in the wash. The laundry monster takes it away. Tags get taken off before it goes in a drawer so it is ready to wear. Picking something without a tag, even if it is too small, is easier than taking the tag off.

I wouldnt do well keeping my fat trap shut either . "SD you look ridiculous."

Best you can do is keep biting your tongue. If anyone at the school says anything to you flutter your lashes and say "BM is firm on what SD wears. I have to respect that"  LOL

it isn't step related but I dealt with having to learn to not take my sons outfits as a personal affront. When he was 13 we had the year of the orange. Everything he wore was orange. Orange cargo pants - check, god awful orange t-shirt, sweat jacket, fleeces, coats, hats ... it took practice to teach myself not to take it personally. He was fully clothed, the clothes were clean, they fit, they weren't raggedy. They were just orange. Really really orange. 

I told you that to tell you this: I understand how you feel. Completely. But trust me, no one is judging you when she prances into school in mismatched outfits. Almost every parent, step or not, gets how you feel. It will pass, just practice ignoring and letting it go.

I look at DH and say, "Tell your son he looks like a hobo and needs to change" in front of but not directed to SS12. I get the eye roll from DH but he is starting to take care of it because I remind him constantly that his child's dress and behavior is a reflection on what kind of father he is. 

Some skids are just cat ladies in the making. I know 2 out of 3 of mine are. Lack of parenting on DH's part, and his refusal to let me have an opinion, have spawned these two. One smells like cat piss and is like 400lbs now. She wears dirty tee shirts, sweat pants and nike flip flops. The other occasionally dresses up but usually lives in her pajamas and never leaves the house. She freeloads off her mom and plays videogames all day. 

I'm sooo happy they don't live with us anymore. The youngest is cool though. She actually cares and is trying hard in school. 

BM is going to be supporting her little monsters for a long, long time. 

Why would anyone bite their tongue if that facilitates toxic behavior?

If it is not confronted, it likely never ends.

It's hard to keep quiet about the annoyances. 

These step kids here are extra picky with food and their clothing looks like they rolled out of a homeless encampment. 

What I do is I usually only am seen in public with them during the holidays or something when their parents actually put in effort to help them with their clothes. 

The food pickiness, I dont even bother cooking for them anymore. I will make my soon-to-be-ex cook for them because I dont' have the energy or time to deal with that. 

I came from the old-school where you eat what is cooked or you can make your own PBJ/turkey sandwich/or cook your own food but these step kids nowadays are uber coddled.

Not my problem not my issue. Any issues affecting your household you notify hubby and he addresses it immediately that day. It may take a while but eventually your husband will get fedup and start addressing the issues on his own. 
 

i myself don't care how skids dress scruffy of sd's like they're in mourning everytime i am there because they make themselves stand out and behave like they are not part of our family and inner circle and therefore are not treated as members of our inner circle