At first glance, the army seems slightly unbalanced.
You have this huge anvil of spearmen but no strong hammer :
The main function of swordsmen and pikemen is to act as a tarpit. 50 pikemen gives you an awful lot of attacks due to the horde rule, however, their strength might not be enough to punch through anything with an armor. Swordsmen have good armor save and a parry save, but also lack in strength, so if your pikes get charged and the sword countercharge, the only thing they'll do is add combat res. If you do want to proxy it and pass your pikemen for halbediers (50 halberdiers, now that's a nice killing machine). I would suggest switching roles. Use your swordsmen (including free company passing as swordsmen) as your main regiment, 5 wide, 10 deep. With Bsb, hold the line, etc., they'll be a really tough nut to crack. and use your pikes as the dettachment just to add numbers for combat res.
Ok, now that you are more solidly anchored on the table, how are you gonna reply to the opponent that gets stuck in your tarpit? You need a hammer. Greatswords usually excel at this, but if all you have are knights, then they either need to be able to roll over whatever opposition they face so they don't get bogged dow, or you need to split them for more manoeuvrability. On that topic, if your general is going to be a hochmeister (grand master) by all means give him a runefang. Then he becomes a killing machine and a monster killer especially. Don't need to give him much more than that : a shield, heavy armor (or is it fullplate) and barded warhorse means he has a 1+ AS. The other knights don't need to be Reiksguards, Innercircle knights are enough provided they are armed with lances. Okay, they won't kill much (but your Hochmeister will take care of that) but they won't die much either. A mounted warpriest is a good idea in that unit for hatred. You could perhaps split the knights 10-6. 10 with lances and including the GM and 6 with great weapons and the warpriest? They might die quick but if they catch weak units they might be able to crush them and that way the entirety of your hammer wouldn't be stuck on one side of the table while your anvil got slowly decimated.
Wizard... definately a level 4, no less! All the schools are good (some better than others), it depends on your opponent. In a case like yours, Beast lore might be good to give extra oomph to your spearmen.
BSB... No magic banner, just tool him so he can't die, with armor and talisman and make sure someone else is there to take challenges in his stead.
Canon is good against monsters or huge targets, otherwise it is a bit disappointing. Hellblaster volleygun with an engineer (a must have) will give you more bang for your buck against rank and filers and cavalry.
Mortar is no good. Consider instead one of the swanky wizmobiles. The huricannum, I believe, gives you +1 to hit. Combined with an appropriate buff from a beast wizard and hatred from a priest, your pikemen suddendly become more of a killing unit.
Captasus... only if you have points to spare and your opponent relies on wizards (dark elf, tomb kings, vampire counts). Same story for witch hunter, although he is quite cheaper and fluffier (as in fluff).
Alternatively, here is what you could do.
50 spearmen, FC, with BSB and warpriest, + detachments of 10 crossbows and 10 handgunners.
Position: Static until the wave hits you.
Canon on one side and the other (if you don't want to pass it as a hbvg) perhaps in a far corner (just like the dwarfs)
Swordsmen and freecompanies together on one side try to roll a flank (you should really pass 30 of them as greatswords and the 20 others as a dettachment). Another warpriest in there might be useful. And perhaps your wizard should bunker with the swords.
Then your knights in one big block (or two like I suggested above) try to roll the other flank and focus on whoever reaches the pikes...
This is by no means to be taken litteraly, more like ideas to explore. It seems to me you have a good army, but in 7th edition. 8th edition Empire doesn't rely as much on spears and really focusses on synergy within large blocks. As such, I find halberdiers are way more efficient than spears... Anyhow.. food for thought