Should Beginners Play an Opening System?
"Besides the Colle System, are there other opening systems that you would recommend a beginner to learn?"
First, let me differentiate between a regular opening and an opening system. An opening system is one where it doesn't matter what the opponent plays: Colle System, London, King's Indian Attack, Modern Defense (to an extent), or the King's Indian Setup. (Even here, there can be a grey area: 1.d4 d5 2.Bf4 is a London and 1.d4 Nf6 2.Bf4 is a London, but 1.d4 f5 2.Bf4 is a Dutch! In this final case, Black's first move determines the opening no matter White's second move).
But most openings do require a specific sequence. For example, 1.e4 c5 is a Sicilian but if Black plays 1...c5 against other first White moves it is not a Sicilian (unless it transposes due to a later White e2-e4). For example 1.d4 c5 is a Benoni. Or you can get into a Gruenfeld with 1.d4 d5 2.c4 g6 3.Nc3 d5 but if either side makes different moves, it is likely not a Gruenfeld. For example, 3...Bg7 instead of 3...d5 is a King's Indian. 1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+ is a Bogo-Indian, but if White plays 3.Nc3 then 3...Bb4 is a Nimzo-Indian.
You can't automatically play the moves from one opening if you are in another. Recently one of my students studied 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 in the Ruy Lopez, but accidentally moved his knight on move three and played 3.Nc3 Nc6 4.Bb5, thinking he was still in a sort of delayed Ruy Lopez. Then when his opponent played the "expected" 4...a6? he automatically played 5.Ba4? overlooking that with his e-pawn guarded he could just win a pawn with 5.Bxc6 dxc6 6.Nxe5.
Back to the original question: While playing "automatic" systems may help beginners survive the opening, that is not always the goal. The goal may be to learn things to get better. In that case I agree with traditional advice that beginners should play 1.e4 and get into Four Knight Games, Two Knight Defenses, Giouco Pianos, and all kinds of "Open" games to get tension and tactics into the position. Delaying the tactics for a few moves with systems like the Colle or King's Indian Attack only delays the inevitable. May as well learn to fight from move one and learn as much as possible, IMHO.
"I would like to model my game after Johnny Hector's style. I like his aggressive play. What do you think?"
Anything that helps, great! I don't necessarily recommend that lower-rated players pick out a particular master to emulate his "style" but, on the other hand, doing so may possibly be helpful. It is especially helpful if the player you pick plays aggressively (good for everyone learning) like Hector. Moreover, you don't need to play the same openings as the player you are emulating in order to simulate his style. Many openings, not just Hector's, can be played aggressively with similar ideas.
I should add that sometimes a player can learn the most from working on his weaknesses, rather than sticking to his strengths. A positional player can get better by playing tactically for a while and a tactical player can learn from having to play positonal-type positions and openings.
In that sense if you are a fierce attacker it would hurt to study a Steinitz, Capablanca, Petrosian, or Karpov, while a tame positional player can likely learn a lot from watching games from Marshall, Alekhine, Tal, Shirov, and Kasparov.
Learning how to imbalance a game and take advantage of those imbalances (shades of Silman...) is a very good lesson - but I would not recommend it much to players rated under 1700. If you can't determine consistently if your move is safe, then emulating a particular player is likely a waste of time...
"After 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.d5 Nh5 8.Qd2 Qh4+ 9.g3 Nxg3 10.Qf2 Nxf1 11.Qxh4 Nxe3 12.Rc1 Nxc4 What should I, as Black, play after 13.Nb5?"
That would indeed be a problem if that were a book position. However, you have the move order incorrect. White has to play 12.Ke2 first as 12.Rc1?? loses the queen to 12...Ng2+. Then after 12.Ke2 Nxc4 13.Rc1 is possible. Black can then answer 13...Na6, and if 14.Nb5 Stockfish 6 suggests the cute 14...Bd7! with dynamic equality.
White to play and mate in 5. Not having much time, at first I considered 1.Qd7+ Bxd7 2.Nd6+ Kd8 3.Re8+ Bxe8 4.Nf7+ Kc8 5.Rd8# But then once I started to demonstrate this, I realized that 4.Nf7+ is easily met by 4...Ke7. So I simply reversed my move order and played the correct 3.Nf7+ first, and then after 3...Kc8 4.Re8+ Bxe8 5.Rd8#
By the way, if this were a game and not a puzzle, and you would have rejected 1.Qd7+ because it "loses the queen to 1...Bxd7" then of course you would miss the mate. Stopping your analysis too soon this way is called a "quiescence error". Instead of stopping you should ask yourself after 1.Qd7+ Bxd7 "Is there any continuation that would indicate that after 1...Bxd7 it is worth analyzing any further?" In this case you should then identify the double checks 2.Nxf6+ and 2.Nd6+ and say "Yes, this merits further investigation; maybe I can eventually checkmate Black!"
September's was the final "Q&A with Coach Heisman" TV show, at least for a while. Due to lack of viewership, Chess.com has decided to go in another direction. With any luck, look for me to start a new instructional column here at Chess.com sometime early in 2016. Thanks for all the questions the past few years, and thanks to all the mods and technical support people for the show! Cya around...