Offensively, Kingdra does a good job of handling Starmie. If you can get Scarf Ttar or Scarf Rotom-A in against it, they can beat it out (Ttar can either Crunch for the OHKO if you think it'll stay in or Pursuit for the OHKO if it's switching out.)What is usually check/counter of LO starmie in balanced/offense ?
When i can find a tour for dpp ?
What is the most popular LGS ?
How to deal with explosion ?
How i stard building team ? Lead/Spinner/anti-spiner and support/lgs/scarf user/stallbreaker ?
And finally how i can reach a good level ? i usually do ladd + searching match in room fr(i am french this is why i'm not good in english and its hard for you to read this :c)
I'll be hosting one next week in the Live Tournaments forum, though I won't know the exact day and time until I see my work schedule in the coming days. Besides Old Gens Tour Nights, they pop up from time to time in the Tournaments forum. In particular, Smogon Tour (which just wrapped up regular season), Smogon Classic (which has already started), WCoP (team tour, starting in about a week, but you'll have to try out for it), and Smogon Premier League (also a team tour that you'd have to try out for, but that's not until winter) are official ones that have it. Other tours happen at various times throughout the year, though~
For LGS, you can try to guess which one they have based on what their team looks like. More than likely, their team will have the goal of wearing down and removing potential counters to their LGS, so keep in mind that it can be pretty much any offensive threat before you risk something without all the details.
Ideally, you'll have something like Rotom-A, Gengar, or Skarmory take it. Otherwise, if you're predicting a boom, try to identify the weakest link on your team to sacrifice. Also, if for instance Blissey is the only thing stopping you from getting swept by X sweeper, be wary of special attackers that might also have Explosion to lure it out (Heatran, Gengar, etc.)
One of my favorite posts on team frameworks in general is by Limitless from an old BW RU thread http://www.smogon.com/forums/threads/how-to-build-ru-teams.3475187/#post-4525198 (Keep in mind that's just a basic starting framework for a general hyper offensive team. Balance will look totally different, and your team itself will likely need to be tweaked as test it out.)
You can ask good players for tips and battles in #ruinsofalph on SynIRC. There's also the Old Gens room on PS. Both are pretty chill places, though they can be pretty quiet chats sometimes.
Hope some of that helps, and good luck, man ^.^