Unless you have relatives on a masjid committee you will have great difficulty. The better scholars have greater difficult than those less knowledgeable.Those with greater knowledge will be seen as 'threat' to those already in positions of power. Those will lesser knowledge will do as they are told. Yet those with knowledge will want to change things and will find shakles of the elders, Imams and 'teachers' upon them like never before.
You come back to a place which is more or less as you left it. Lots of infighting, useless masjid committees and ignorance as prevalent as before. You will not have anything ready for you or expect any assistance especially local communities. They will not be able to accept you as a teacher.
The masjids are boys clubs were ignorance learnt in society is confounded. Masjids have great opportunities to counter the ignorance but do nothing. They do not want to pay a reasonable wage for a teacher, so your kids are stuck with an ignorant elder.
So what does the qualified teacher do? When he is blocked by the masjids into reaching the people who are dying for it? It's clear that most masjid committee members are sliding into hell. Inflated egos and ignorance prevent learning of any kind. Millionaires would rather buy anything than pay their precious zakah.
Forget any notion of being supported except by a few. Set up your own madrasa/ school and have some sort of day job. You will need your day job. No one is going to help you support your family. Get a day job and do something that frees your evenings and weekends up. So you can teach etc. Start slowly and it will take years that is without doubt.
Then again you might be lucky and get some support. But it is humiliating to be in a community that does not appreciate your knowledge or come to learn from you. Even though the doors are open no one enters. It's humiliating to have spend years studying and to be offered £150 a week. Or be paid minimum wage when masjids and individuals have millions. Yet do not want to help. In one way or another it's humiliating to be a teacher.
The novelty of someone calling you sheikh wears off quite quickly when you realise that you do not deserve it. And that most of the people of your area will never accept you. Wealthy individuals have as much to answer for as the masjd committees do.
You have to be that change in the world because you cannot rely on people to change. And until you do something the wretched state of our masjids will never change.
So build something new and start over, let the fools squander public money on toilets and you concentrate on building something much more precious than bricks and mortar, building a grounded knowledge person who is Muslim.
That which has proved elusive to all these boys clubs on the whole.
Millions of children are neglected by not being taught properly but you do not allow a single child to be left out. Your reward will be greater, it's not about numbers it's about percentages. Even reaching one person is enough but do not expect the people who should be helping, to help you. Know most famous speakers have no knowledge and are just good at talking. You would be shocked to learn that most speakers and teachers have empty titles. They pretend to be hanafis but do not follow hanafi works!
So let the kids play and you get started at the grass roots level. Where the real work is done. Let the inflated egos get larger whilst you spread knowledge.