1. No seas melindres
Melindre is a type of pastry or sweet cakes. Used metaphorically in this way, it refers to affectation or squeqmishness. As Amparo says, this could be rendered as, "Don't be picky" and perhaps also as "don't be finicky" or "stop hemming and hawing".
Don't be a _______
2. Los rogelios no respetaís a los mayores?
Respetaís = you guys don't respect.
The ______ don't respect the elders
You Rogelios don't respect your elders.
3. Dar la cara con la gente en el barrio
Dar la cara = face the consequences of your actions, face the music, show your face, stand up (for something).
I usually see this used with 'ante' rather than 'con' so my guess is that here it says to stand up with the people of the barrio. Maybe a native speaker could clarify this differnece.
______ people from the neighbourhood
4. Lo siento pero no puedo quedarme a la función
I'm sorry for not being able __________
quedarme = to remain or stay
la función = a show or performance (in this context)