Guangxi Clique may not have what it takes to become a major power, but it can become a vital player in China's fight against Japan. As one of the Chinese warlords, Guangxi Clique will automatically ally with the rest of china if and when the Japanese DOW sometime in mid-1937. Your first year and a half should be devoted to preparing for this war.
You start out with a pretty good sized army, with a makeup of about 1/3 militia 2/3 '18 infantry. Overall, a well equiped army for such a small nation. All focus should be directed at infantry. Some mountain and cavalry troops might do some good as well, but a navy and airforce should be ignored entirely. You lack the tech teams to research these areas, and even if you do, the Imperial Japanese Navy will crush you. (not tested as of yet, but building some interceptors might help in keeping the japanese bombers out of your skies). Now you see why Guangxi Clique does not have any chance of becoming a world power.
This area is quite straighforward. You have +199 relations with most of the other Chinese factions. However, don't pursue an alliance with the Nationalists right off the bat; for some reason they never accept. wait until the Japanese invasion when the alliance will happen automatically. If you want, you could go for the lands of Yunnan early on, and crush them in a matter of months (the only limiting factor here is the horrible Tc you'll have). This gives your troops some extra experience while granting your industry a slight boost (around 6 IC). However, your sliders all start out very far towards the right, and due to your isolationist leanings you will get a massive dissent boost any time you delcare war. Therefore, a strategy similar top that used for Argentina will suffice. Stock up on supplies, then when the war starts, devote all IC to consumer goods. The dissent should abate quickly. It will of course be tempting to take Tibet and Sinkaing after you deal with Yunnan, but their lands have nothing of interest, and a war in the Himilayas is generally not a good idea. It will also tie up troops far from the action once the war with Japan starts.
You can also pursue an alliance with Yunnan if this is done very early.
Economy and Tech Teams
Lets face it- your economy is mediocre at best and you tech teams are primarily suited for infantry research. You should have the technology for '36 infantry by mid 1936. From here on out, you want to upgrade all of your land forces; only train new units when all of the upgrades are carried out.