Recently widowed - Tax advise

I am recently widowed and make more than would allow for survivor benefits.  In fact, I will be hit next filing year when I have to file single again.   Questions that may not be able to be answered but would appreciate it if I could get pointers to where I can get more help. 

 

How do you balance when to do a roth conversion vs.  taking an ACA supplement? 

 

When I am single and my deduction goes down?  How can I keep track monthly if my ACA is in compliance?  

 

How much income before you get hit with tax penalty if i am below tax withholdings (looking to retire and take income out of 401k). 

 

Thanks