What Game Mode Should I start off with?

Yes, rewards go up with difficulty. See here. Crowns on Normal are 33% less than crowns on Elite. Crowns on Advanced are 16% less than crowns on Elite.

From 2011/04 to 2013/07, there was only one difficulty level, which we now call Advanced. This is the difficulty, on which the game was designed to be played. Arguably Advanced should be called "Regular", Normal should be called "Easy", and Elite should be called "Difficult".

My recommendation is that you play on Elite, until you start spending Sparks of Life. Then play on Advanced, until you start spending Sparks of Life. Then play on Normal. Then try Elite again. Basically, play on the most difficult setting that doesn't frustrate you. Cheers.

My suggestion for your difficulty is to start doing the lower ranked missions on Normal because they have minimal payout. This may also you to hone your skills a bit.

Missions starting from Rank 3 can be played on whatever you want, as they give more money then lower leveled missions.

Elite difficulty will probably kick your butt in the later levels, as enemies will start robbing you of about a fourth of your health, but care, speed, and reflexes will keep you from getting incapacitated in the clockworks.

Thx for the info, rly appreciate it :))
However; I don't know what choice to choose from, Bopp or Blazecat-Percival
I guess I'll experiment with both in the arcade and see which choice is better, still, good info
Again, thx for the info

~Volkheir

personally, I would recommend elite all the way, as far as you can without having to use sparks. even if you dont get that much money for it in the beginning, it is still a good idea to have you train a little.
additionally to what bopp said, other things like rarities and materials are also found more commonly on elite. you can also find some things a little higher up.