Isn't there also a restriction on the amount of energy you can play? Maybe per pokemon? I seem to remember there was something going on there...
Yep, you can only attach one energy card to a Pokemon you control each turn.
In response to Jason's article: you're spot on about the differences from Magic. No competitive Pokemon player that I've met plays Limited. It just doesn't exist. Oftentimes, people attend a prerelease or two as they start becoming more invested in the game, but as soon as you get into Standard, you realize that this game was never meant to be played as a Sealed deck.
Card distribution is a lot more frustrating on the online client. The paper scene is actually much easier to get into, in my opinion. Once you have all the staples (largely comprised of the very strong Trainer cards, which rarely surpass prices of a few dollars at most), you can build decks very easily, because 20 cards or so are going to be shared between every deck. If you even need Special energy, you should be able to pick them up for 50 cents apiece. In the physical realm, trading is extremely common, more so than in MTG, I'd argue, and you can effectively swap out the Pokemon in your deck (by far the most expensive type of card, unless you're playing Expanded) for the Pokemon that you need to convert it to another Tier One deck. Once you make some friends that you playtest and brew decks with before each tournament, you also are provided a network of people that will happily loan you cards. Finally, booster packs are awarded freely at the events (which used to be entirely free to enter, though are still cheap) and these will keep you supplied with staple cards and a few valuable cards to use as trading ammunition.
When it comes to deckbuilding creativity, I think you'd be very surprised. Even though so many slots of your deck are shoe-in staple cards, the search and draw power they provide make it quite likely to see any given individual card in a game. As a result, you are faced with a plethora of agonizing choices in deckbuilding. In Magic, your deck is almost entirely comprised of 4-ofs. Pokemon lists will have 30-45 cards taken up by 4-ofs that are critical to your deck, 10 or so cards taken up by energy, and only 2-10 cards of flex space, depending on the deck. But these flex spots go a MASSIVE way to setting your deck apart from the field. There is no sideboard, so any slots spent on countering other decks uses precious space in your decklist. The term for these silver bullet cards is 'tech' in Pokemon circles, and they can tilt a matchup in your favor by as much as 5-10%, because you will be able to find the card almost every game with the incredible search and draw power you are already playing. But there are almost zero cards in Pokemon that can completely hose an opponent's deck. There isn't a Leyline that can win you the game by existing in your opening hand. In general, balancing your deck between consistency and the inclusion of 'tech' is a big deal in Pokemon.
Metagaming is a much larger focus in Pokemon, and every competitive player will be trying to scope out and predict what the field will look like before a tournament, selecting a deck accordingly. It's so easy to change decks, that even if you know what someone was playing last Sunday, you will have no idea what they might be packing today. Matchups between archetypes also tend to be more lopsided, which is unfortunate for game quality, but this means that choosing the right deck for the event, and building it accordingly, can catapult you into the forefront. To be honest, this aspect of Pokemon looks more like gambling than anything present in Magic. But the price of attending a tournament is so low that this ends up being a feature in many players' eyes... there will always be a good excuse for not doing well that day, and there will always be something to talk about, with the metagame constantly changing at lightning speed. Overall, it really is a fantastic, incredibly accessible game. Typing this makes me want to get back into the scene! There's a rotation coming soon, so now's the perfect time to jump in...
The two major skills in Pokemon that can set you apart are metagaming/deckbuilding, and sequencing (as you play a ton of cards per turn, and eking % points out of each of those actions will yield high benefits in the long run). So if these are your strengths, you will almost certainly do well.