If I'm understanding you right, your main goal is to make your pushbutton responses behave like a toggle switch, where you press it once to turn on, then again to turn off. I'll neglect for now the fact that button contacts usually need to be de-bounced to do something like this. One solution:
static uint8_t b1State = 0;
static uint8_t b2State = 0;
static uint8_t b3State = 0;
static uint8_t b4State = 0;
int b1value = digitalRead(A0);
int b2value = digitalRead(A1);
int b3value = digitalRead(A2);
int b4value = digitalRead(A3);
if (b1value ) b1State = !b1State;
if (b2value ) b2State = !b2State;
if (b3value ) b3State = !b3State;
if (b4value ) b4State = !b4State;
so the state vars (b1State, etc) now basically reverse and hold their state variable with each button press. Again, this won't work well unless you denounce your buttons, and its not taking into account that though you may THINK you're pressing all the buttons at the same time, they really happen at slightly different times. Now if you must have all buttons (or whatever combination of buttons) register at the same time, you could consider a 5th "ACTION" button, whose purpose is to start whatever process you want, based on the buttons pressed. In this case, we're not "toggling" button states, but just making them "stick", so the debouce is less necessary.
static uint8_t b1State = 0;
static uint8_t b2State = 0;
static uint8_t b3State = 0;
static uint8_t b4State = 0;
int b1value = digitalRead(A0);
int b2value = digitalRead(A1);
int b3value = digitalRead(A2);
int b4value = digitalRead(A3);
int b5Actionvalue = digitalRead(A4);
if (b1value ) b1State = 1
if (b2value ) b2State = 1;
if (b3value ) b3State = 1;
if (b4value ) b4State = 1;
// and now for your 5th, ACTION button, pressed afterward...
if (b5Actionvalue )
{
// do your LCD output based on the b1State through b4State values
doMyLCDstuff();
// then, clear all your states, to be ready for the next action
b1State = b2State = b3State = b4State =0;
}