Miners will mine the coin if the coin is profitable.

The coin will only be profitable if people buy the coin.  Not mine it.  Mining the coin does not make it profitable.  Mining the coin dilutes the value causing it to be worthless.

I was holding the coin's value at 100 Satoshi.  I dropped my buywalls to 50 Satoshi because I got tired of subsidizing half a million coins a day that miners were dumping on the market. 

When the update happens that restricts the amount of coins being mined, I (and other investors) can buy the coins and raise the value.

As the value rises, you and other miners will mine it again because it will be profitable.

Volume of coins mined has nothing to do with your profits.  Only the value of the coin itself. 

Now, you need more consumer facing features to really enable this coin to take off.  You can't just restrict supply and expect people to invest.  People will invest if this coin is innovative and provides features that other coins do not have, and that consumers and businesses are going to want to use.  That way they adopt the coin for reasons of commerce, and that causes the coin's value to grow beyond speculation.

Growth increases the mining reward, increases volume, and your mining profit.

Having a coin that is developed to attract miners only is a waste of time.  Miners will mine the coin if it is profitable. That's all they care about.  Making the coin profitable is the developer's job to make it so the coin is worthwhile to investors and consumer facing adopters.