For now the only way for me to create skins is to code them in Sta.sh. But in Sta.sh the work turns out to be incomplete since it doesn't contain the moodlists. All the same time in regular journal I have only one place to observe my skins (the preview window in "Edit skin" section), but that place displays skins incorrectly (in fact I don't know why: when I contacted Help Desk, they said they don't have such a problem). So I thought that the only possibility for me to resume creating skins is to become Core: though I'm not sure that standard preview window will show them properly, it's the only thing I didn't try yet.
In order to achieve that, I started this donation pool. Thanks to everyone who'll respond.