Both sentences given are slightly incorrect, I’m afraid. I think the form you want is probably
I wish I had been there for…
(In speech or informal writing, this would often be contracted: “I wish I’d been there for…”) Also good, as Robusto said, is
I wish I could have been there for…
although this only works if your absence was unintentional — if you knew when to expect it and just chose not to go, this version doesn’t apply.
The versions
I wish I were there for…
I wish I was there for…
are appropriate for an event happening right now, not for something that happened in the past. You might have a phone conversation: “The baby is kicking right now!” “Oh! I wish I were there for it!”
The form
*I wish I have been there for…
isn’t correct for anything (although it’s a fairly common error among non-native speakers, and people wouldn’t have difficulty understanding it).
Yes. Using right now emphasizes the time and implies that some condition is currently being experienced that prevents the connection but with the expectation that it will be corrected at some point in the future.
We can't connect right now, but hopefully it will be fixed in an hour.
Using just now may imply that some general condition has changed that is not temporal in nature:
You asked me to disconnect that cable, but I can't connect to Outlook now.
or it might be used in the exact same way as right now albeit with perhaps a little less emphasis on this exact moment.
Best Answer
The meaning of the verb WISH changes according to what type of Complement it takes. When the verb WISH is used with a finite content clause , the meaning is counterfactual. We do not expect the thing described in the subordinate clause to happen:
Notice that when we use a full finite clause after wish the tense is backshifted. The examples above, for instance, use the past simple was even though they are talking about the present. Notice that we cannot usually use will in these clause, we need a past tense form.
When we use the verb wish as a near synonym of want or hope, then we cannot use a finite clause afterwards. We need to use an infinitival clause:
The use of wish in this type of sentence is relatively rare when compared to its use in the sentences further above; the other uses are far more frequent. When they are used, these sentences using wish are often used as a form of request, as opposed to as just a description of our mental state. They are quite formal in register.
If we use the verb wish with a Direct and Indirect Object, we also present the thing that is wished for as an actual possibility: