You are lucky that you have an apexi, that makes getting her mapped around 500euro cheaper than a map with first time ecutek licence,
Dont know what car you have, but the mods you are talking about should be bundled together as a stage 1 package
Walbro fuel pump, pfr7b plugs, Exhaust system, and uprated drop in panel filter (my recomendation) or an induction kit.
Remap for these mods and a good fuel like e5, and your car will be transformed, There is really no way to explain the difference it makes, it will be rapidly faster than from the factory, and in most cases drive better.
My first ever mapped car was a 00 sti, with the mods above, and drop in filter and i only got the car mapped for straight 95oct.. and it was a serious piece of kit to move, like everyone else, i was stuck on the price of the map, and didnt know what to do, i had to ecutek which was around 1000 euro... but well worth it, and i would spend it in a heart beat again.
If you are not going to map her, then just leave her alone, as you are only tapping into about 10% of what she could be with a map and thats without taking into a/c the risks that are run without a remap..
when i fitted a straight through system i couldnt drive the car as it kept oveboosting and fuel cutting, had to drive off throttle until i got mapped