这句英语表达有问题吗

帮你改了改...

If they sincerely express their gratitude, we don't care how they choose to do it.

有很大问题，处处都是错！

you use "only" and "everyone", these two words are conflict.

take out the only

语义有些问题

If only 虽然中文是 可以翻译成 只要 的意思
但是 实际上他有 要是... 就好了的意思 就是说 If only引导句子后面应该是一个正面的意思
比如
if only he had been there
他要是能在该多少啊

she would be a good player if only she could get it together
他若能控制得当就能成为很好的选手

前后有一些因果的含义

但是根据你的句意 as long as

后街有首歌 as long as you love me
就是 只要你爱我（其他的都无所谓）的意思 前后有一点转折的含义

语法上也有些问题