我的问题是,现在我要帮他办SVP必须找个PR担保对吗?
ans: yes

像是我同学去年毕业的现在是PR也可以吗, 这样的话就是以访友为目的的对吗?
ans: yes

这样办下来的可能性大吗?
ans: not affected

我可以在回去之前帮他办好签证带回去吗,
ans: can

签证是一办下来就开始算时间还是到新加坡以后开始算时间?
ans: must enter SG within 30 days after being granted the SVP. the stay time counts once arrive SG

这样的签证一般是30天的对吗?
ans: 14 days as entry visa. once get SG, go to ICA to apply for SVP. can go to ICA on 10th or 11th days so to enjoy longer stay. ICA only need 1 working day to process SVP application

或者大家有经验的有什么更好的办法呢?
ans: no, it's quite standard as i know

ENTRY VISA 和SVP 什么区别啊, 我听说ENTRY visa办起来快一些,可是有效期是多久啊,可以延期吗?
ans: if your BF is not in SG, can only apply for entry visa; and he will get 14 days stay granted on entry point after alight in SG. then apply for SVP together with a PR at ICA within these 14 days. the stay for visit pass is from 14 day to 3 month. (usually 1 month or longer). extention is considered case-by-case. may get longer, or not, both possible. even cannot extend, they will give you another 14 days to leave SG.

Let me know if need more help.