10 Years Long Residency With Dependent

I am on Tier 1 Entrepreneur visa 50K Extension, My visa is expiring on 10 Sept 19.
I have 3 dependents
1.My wife is my dependent since 23 May 2014, she got PBS Dependent Visa
2.My son Born in UK in March 15, got UK birth certificate and also got a dependent visa since June 15
3.My daughter also born in UK in April 18, got UK birth certificate and got a dependent visa in Aug 18
I am eligible to apply on 10 years long residency on 15 Aug 19

My Questions
1.Can I apply for 10 years long residency on 15th of Aug 19 ALONE at the window
2.Once I receive my acceptance and visa can I apply for my wife’s ILR within 10 sept 19 instead of making application at the same time as me? The reason is that the fee is too much and in case if my visa is refused then I don’t lose my Wife’s visa fee at the same time as me
3.Can I apply my son and daughter’s nationality once I get my ILR instead of applying for their visa extension?

1.Can I apply for 10 years long residency on 15th of Aug 19 ALONE at the window

Yes, however same day decision might not happen

2.Once I receive my acceptance and visa can I apply for my wife’s ILR within 10 sept 19 instead of making application at the same time as me? The reason is that the fee is too much and in case if my visa is refused then I don’t lose my Wife’s visa fee at the same time as me

Your wife cannot get ILR under PBS as you get ILR under SET(LR). She has to switch to FLR(M) and her ILR clock will reset to zero

3.Can I apply my son and daughter’s nationality once I get my ILR instead of applying for their visa extension?

Yes, you can register them once you get ILR