seems fine, as pre flop 3 bettor u may concider cbet cause ace fits ur range fine ( tho cold caller as well ) but once u check ur range is rather face up - pair lower then ace

Since u raised to 521, half pot c bet would commit ur stack in WBWA spot so it is very bad idea, but  may try different bet sizings that allow u more manipulation

Smaller bet sizes pre flop and post flop allow u much more room to play, yet get it in big pots will happen anyway when u decide too, so betting smaller pre flop won't hurt amounts u wil win in end, weaker ranges wil have odds to call you and u wil gain value there, your bluffs are cheaper, so u may reconsider sizings

Eh, I don't know, with this much money already in the pot I don't mind betting either.  He should have enough Jx that will call off because he's committed, although it kind of sucks that you block KJ.  

I was thinking 3 bet to 460 - c bet 1/3 that looks like value bet would leave him around 1200 if he gets called, he can shutdown on turn, but since he 3 betted and c betted his hand wouldn't be as face up as when he just check the flop as pre flop 3 bettor  . After that HJ has every incentive  to try c bet with any holding , 1/2 pot being amount that wouldn't hurt his total stack if called, and on other hand he has many reasons to believe it wil take it down right there. If he was led into with 1/3 pot i don't think he would have any decision to make but fold if he didn't have Ace. This way, we have no idea what to do and what he has in hand, and it could be avoided IMO if diff bet sizing was used. Smaler bet sizes pre flop are very popular, and main reason are that if you have great hand , ppl will call of laid pot  odds more often just to check fold the flop and you wil gain value, and same time if you have total air ppl wil fold again way to much, and times they do have a hand , price on your bluff was way cheaper. Also at times it allows more post flop playbility , for example as now when ur stack is not huge, but u do need to c bet. 

It's already $450 in the pot.. i think i preffer here shoving PF rather than min-3b and c/f flop.

There is a limper, a raise to 2x and u have 18bbs left.. i Think shoving PF is the right move here. 

With a deeper stack a raise to 521 is so small, you have to give them the chance to make mistakes, so you at least had to put him in a position of "raise all in or fold" with a raise around 800. 

Dont forget that in sngs for this level people are not much into studying theory or maths. they are just curious, they just want to see flops (most of them) so bet strong with your premium hands pre flop and C bet them every time, they fold more than you can imagine.

gl!