When hovering over an ability, the tooltip will tell you whether or not that attack is weak or strong against certain pet types. Additionally, you can hover over the opposing team's pets and view their attacks during combat. This will be important since it’s a good idea to pit a pet that's strong against the opponent's pet who's vulnerable to that type.
Although the Battle Pet Trainer will only offer to teach you your race-specific companion, it is possible to add all of these pets to your collection. You can either find them in your faction’s auction house or you can create a character of the race whose pet you would like to learn. Using your new character, you can seek out any battle pet trainer in major cities. After you learn the pet, you can delete the character; the pet you learned will not be removed from your collection.
For example, the Azure Whelpling belongs to the Dragonkin family. However, it has Beast, Magic, and Elemental abilities in addition to a Dragonkin attack. Different attacks are strong and weak against different family types. Having a diverse spell selection might increase your chances of being prepared with a strong attack against an opposing team.
I consider myself a purist in that I would prefer classic to be released as close as possible to the original. Where that is on the spectrum of patch content will be up to blizz. I'm also not vane enough to believe that any single state of the game is the "Ideal" location we should be aiming for. There is common ground that we can agree on, and I would welcome more than a few changes as long as they are made in the spirit of keeping classic on the vanilla rails.
Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.

They seem to have expected some things, though, see adding pets with aquatic damage (gun and ooze) aswell as a resistant cockroach to stop us from cheesing everything with elementals. Yet, a fact their damage output is low combined with shields not checking for racial damage means this mechanic prevents a lot as you mentioned. The last boss has got an ability to remove basic shields so perhaps that was not in oblivion either… unlike the reactive damage. Also, an ability that forces swap altogether with an ability which prevents from being swapped, including critters? I can't say I like it.
Bioelectric Blast (Deadly) - Blasts the target area with electricity. Inflicts 65,654 Nature damage to enemies within 8 yards of the impact and creates a patch of Electrified Ground. Electrified Ground inflicts 14,882 Nature damage every 2 sec to players within it. Shock Burst (Important) - Inflicts 4,377 Nature damage every 2 sec for 12 sec. Upon expiration, strikes all players, inflicting up to 26,261 Nature damage. This damage is reduced the further away players are from the blast. Electric Discharge (Healer Alert) - Wekemara discharges electricity from itself. Inflicts 13,131 Nature damage that chains to additional targets every 1.5 sec. Submerge - Upon reaching 50% health, Wekamara will submerge and summon Spawns of Wekamara. Electrified Splash - While submerged, Wekemara rains electrified water from its pool. Inflicts 21,885 Nature damage to enemies within 3 yards of the impact area. Spawn of Wekemara (Damage Dealer / Tank Alert) Charged Bite - Inflicts Nature damage to an enemy Conductive Spittle - Inflicts Nature damage to an enemy and increases Nature damage taken by 50% for 16 sec. Loot Tables
Learned this today: posted a comment, came back later to see if there was any feedback, reloaded the page: the page posted a copy of my comment. That was not what I wanted. I just wanted to check if my comment was posted and if there were some responses. I did not want to post a copy of my comment from 5 hours ago. And, a humble guess, I think the majority of the users are not expecting such behavior either.
 ":"  -  Any time a step ends in a ":" instead of a "." means that the next step is part of the current step you are on.  This generally means the next step should be done while working on the current step.  This means every "start working on" or "continue working on" will end in a ":".  But this is used with other occasions as well, so keep this in mind.
Zygor was the home planet of the Zygons. (PROSE: The Bodysnatchers) It was known to be warmer than Earth and covered in water, which was in the form of lakes with a different mineral composition than those of Earth. There were also no icecaps on the planet. Native lifeforms of Zygor included the unaltered Skarasen and the Zygons. (TV: Terror of the Zygons)
For the duration of the fight, creatures in the immediate area will not be visible to you (but they may still attack you if they wander too close). Keep in mind that other players will still be able to see you and attack you if you are eligible for player vs. player (PVP). Other players will also be able to view your pet battle in real time, including the pets involved as well as their health as the match progresses.
Peeling is a very overlooked aspect of group pvp. Some classes are better than others at taking damage. If I play with a Holy Priest partner, and I'm an Enhance Shaman, I'd much rather have the enemy attacking me, than attacking my partner. Obviously you can not taunt in PVP, but what you can do is snare the enemies attacking your priest friend, CC them, damage them.. do whatever you can to buy your priest friend those valuable seconds.