Firstly, how did you end up calculating a take home pay of 30000SEK? According to Skatteverket's (Swedish HMRC) own calculator, your take home pay would likely be in the region of 42000SEK.
Secondly, if you can demonstrate that your role is a highly specialised one, then you might qualify for tax relief for the first five years - this means 25% of your income is exempt from tax (so this would give you a take home pay closer to 50000SEK). There is more info here: forskarskattenamnden.se/. However, you can't apply until you're in Sweden, and while I know people who have successfully applied for this, I know others who have been unsuccessful, so it's a bit of a gamble.
Regading living costs, I'd say a take home pay in the region of 40k is doable, but it won't be a life of luxury necessarily. Most families (unless divorced/separated) are two-income households, and prices, especially rents are geared up to that. Depending on how central you want to live, you're probably looking at at least 13000sek in rent for an apartment in the suburbs - easily double that for somewhere very central. There are cheaper flats available, but you usually need lots of years in the housing queue to have any chance of getting one of these. If you haven't already done so, take a look at www.blocket.se to get an idea of the cost of renting or www.hemnet.se for the cost of buying.
There is no such thing as council tax, and if you live in a flat then usually heating is included in your rent, so you'll save a bit of money there.
Groceries are more expensive, but not hugely so, I'd say. We're a two-adult (no kids) household and usually spend around 1000sek/week.
The main thing that's expensive in Sweden are the non-essentials: alcohol, eating out, hotel accommodation, etc. However, most Swedes I know love the outdoors and I think (based on the people I know with kids) it's much more common for people to just meet up outdoors, in outdoor playgrounds, parks, forests, etc. My impression if people are more likely to go for walks or engage in other outdoor activities which cost very little money.
For comparison, my husband and I have a combined income of around 50000sek/month and our rent is 12500sek (we're not in Stockholm). We don't place much emphasis on luxuries, but we can afford everything we want, including holidays, day trips, occassional eating out, etc and put about 10000sek into a savings account every month.
Finally, it's maybe worth noting the non-financial benefits of working in Sweden. My sense is that employers here are much more supportive of parents. I don't know the details, but I believe parents get extra days off parental leave that they can take until the child is 7, which makes it easier to take additional time off during school holidays, when kids are sick, etc. I personally find work-life balance to be much better here, though it might be different in your specific industry of course.