Post [Q] Intense lag on call receiving

Hello everyone.

I'm running on cocore 9.8 and ikaster's pure vanilla rom, with hungarian baseband. I would say I'm moderately satisfied with the phones performance most of the time. I mean apps run smoothly, except when I have a program running(lets say WAZE, facebook, clash of clans, or even poweramp) and I get a call. This makes the phone lag hard, if it manages to proceed to showing the dial screen in time, and I get to actually pick up the phone, it still lags for about 5-10 second while the calling party is waiting for me to join the conversation. What I must say could be really embarrassing and annoying. What I am looking for is a solution for this. What I thought about, is to set up a process what clears my memory, or exit the application running right when the call comes in. Since 95% of the time I'm not doing anything uninterruptable on the phone (clash of clans or facebook) I wouldnt mind shutting down Everything for a call. Because it's a phone afterall, and I want to be able to pick it up.

I'm also ready to switch rom's if it is necessary to obtain better multitasking or prioritizing, if it's worth the hassle. I've been reading the hyped roms lately, but the responses are pretty mixed, and I'm not confident enough it is worth spending hours on installing a different rom(i know installing takes minutes, but costumizing, installing applications, and generally getting familiar with the new stuffs could take a whole bunch of time), I would love to try them all, but I just dont have the time to mess around with it. Besides I have work calls to make quite often. I'm aware that you are not allowed to recommend any rom (try it for yourself is the policy), but I would like to know if you think I could get better experience if I switch maybe to the indian baseband or the latest italian, or go with cm 10.2, even if there is any way to fix this problem.

How i got along with the phone is that I clean the background applications mostly after I'm done using the phone for now, this way it responds fine, and works alright. But sadly I can't do that when a call comes in. I don't even understand why this is have to go this way, since what I've read is that the OS should deal with the background applications and ram management, but somehow it doesnt seem to work as smooth as it should and it often requires manual cleaning. Also i do not use task killers (i've read they do more harm than good), I do it manually long pressing the home button.

again what i see as the easiest and 'best' option is to find a way to make the phone do this automatically whenever a call comes in, and possibly do it before the ram gets filled up and the phones goes numb.

Thank you for your help in advance