Unity Member subscription game More security? IDEAS?

Ok so for my shop i'm trying to do as much stuff serverside as possible. however i am running into a few issues i need help solving.

tha same is done with subscription unity asks weather u are a member then displays member locked content tho agian the .setactive act is handled by unity and could be broken into easily by changing the text in the game.

i have all this working right now tho it requires Unity to ask server for if they have x item or x gold in their MYSQL then unity stores it in Text.text = reselut and then revernces it to spawn downlaoded characters or activate buttons this float can be hacked is their a way to do all this serverside?

examle if ( shipselected.text = 1){//download and instantiate prefab} or if (SpaceGold.text => 1000) {gameobject unlock.Setactive= true} // not as big a issue since this sends a request to a php and is again calculated to make sure they have enough ingame monney

1 when u select a character in the game it asks the database if you have the character then downloads it from the site however a float is stored unity so it knows what character to ask the databse for however people could just change this float inside unity without quaring the server and bypassing this.

2 in my shop where people use earned in game monney to by characters how can i make the available to buy and not enough gold buttons trigged outside of unity so again i do not have to store any vairables in unity and unity is just displaying everything thats the server tells it to by PHP?