1. It's not tenseless. I simply feel that the words 'present' and 'past' are not very helpful names for these tenses as they operate in modern English. I think that terms such as 'unmarked' and 'marked/remote/distancing/' would be less confusing. However, the current names have been used by so many people for such a long time that they are unlikely to change.
2. In that the present subjunctive is so rarely used by most speakers of
British English (
AmE is different), I have found it far easier to present the occasional subjunctive forms still used (
if that be so, long live ... , etc) as fixed, idiomatic expressions. Where learners have previously learnt about, and use correctly, a present subjunctive form, such as
I suggest that he come, I do not claim that the subjunctive does not exist. I do, however, point out that many speakers would say
I suggest that he should come. I also point out that
I suggest that he comes is acceptable to most speakers of
BrE.