For example:
If none of you are coming out, I might aswell go home.
You keep bugging me,geez, I might aswell go home.
不如回家算了 Bu ru hui jia suan le.
Could you use “gan1 cui4” ? Or is it more “I’ll just go home”
乾脆? yeah you can use it too i think 
Ni hao. Zheige shi xue zhongwen de forum dui bu dui. Weishenme nimen bu yao yong pinyin lienxi yixia. Wo zhidao wo de pinfa, wode wenfa bu hao, keshi cong shangxiawen ni yingai hui dong wode yisi. Yichien wo zhende xihuan qu tealit dot com liaotienshi fangjian lienxi wode pinyin, keshi xianzai bu hui. Ruguo nimen yao gen wo lienxi wo hen gaoxing. Xie xie ni. byebye byebye P.S. chin jiuzun wode pinfa he wode wenfa. 
'Yichien’should be ‘yi3 qian2’ and ‘chin’ should be ‘qing3’
Wo xiang zhidao wei she me ni bu xue hanzi? wo jue de hanyu pinyin bu tai hao kan, er qie ni de zhongwen shui ping kan qi lai hai bu cuo-you jiben liao jie. ruguo ni xue hao le hanzi, ni yi ding hui fa xian ni de zhongwen keyi jing bu de hen kuai.
Ni hao lihai! Xie xie ni jiuzheng wo de pinfa. Dui bu qi wo bu zhidao hanzi. Xue hanzi hao nan o! Wo hao lao ren. Hen ben. Suoyi bu hui xue ba.
And ‘lienxi’ should be ‘lianxi’, and ‘yingai’ should be ‘yinggai’
And the reasons we don’t use pinyin to communicate, I guess, are firstly that that would alienate absolute beginners, and secondly that not everyone learns pinyin. Most do, but not everyone.
Sometimes bad pinyin looks like “go pee boo tong”.