Hello! I hope you enjoy it here, to answer your questions
• Yes! However you can only sell makes made from patterns here on Ribblr and from patterns you own, the designer will even get some money for this when yours sell!
• this can be hard as for the most part patterns have similar sections to others, like magic ring/circle and basic shapes are all basically the same, as long as you didn’t steal parts of a pattern it will be fine after all bees, leggy frogs, etc can all look the same and be written similar but as long as you made it yourself it’ll be fine
• there really isn’t anything unwritten it’s basically all written to view, of course you can always ask if you’re curious/not sure 
Something I try to do for newcomers if you ever need help never hesitate to ask in the community, if you need immediate answers feel free to use the help center, search in the community, or the wiki [link below] and community guidelines if needed Happy crafting! Hope to see your crafts soon as well