Yes, Ms. Wack & Ms. Micky,
You please need not bother about his non-appearance in either divorce petition or in maintenance petition, if it is filed separately.
The law insists that the notice has to be served on the opposite party properly. Once, it has been served and he receives the notice but does not appear then he will face all the consequences of ex-parte proceedings. If he refuses to receive notice and the posal person/process server makes his remark on the notice saying that he refused to receive notice, then also exparte proceedings are initiated and your will be given exparte divorce decree. I thnik you have no problem with that.
Now, the question comes about your maintenance issue. Once ex-parte maintenance order is passed in your favour and in favour of your children, the following things arise:
(a) If the order is under Section 24 or 25 of the HMA, You can move execution application for its implementation. First of all it would be seen that if he has got property, it would be attached and sold and out of the sale proceeds, your maintenance will be paid. If he has alienated from immovable property himself with malafide intention, then arrest warrants can be issued against him and till realisation, he may be put behind the bars.
(b) Almost similar is the case in respect of maintenance petitions under Section 125. In the case of maintenance under domestic violence Act (I strongly recommend you to file maintenance under domestic violence Act), the arrest orders can be issued against the husband if he does not pay maintenance and it is criminal prison, which is different to civil prison (you need not to understand the difference, but in your case, the criminal prison is beneficial to realize the maintenance).
I hope, I clarified all your doubts.