In both language, the future is spared since "demain/tomorrow" makes in clear that it is a future action.
but if you want to be very correct, you can say "je vais aller à Paris demain" (near future) or "j'irai à Paris demain" (simple future).
The previous example had 'Je vais en France' --- I am going to France. This example gives 'Je vais à Paris demain' -- I am going to Paris tomorrow
Why is it that we use 'en France' in the previous example and 'à Paris ' in this example , both to denote that we are going TO that destination? can both methods be used?
There is a lot for you here: http://french.about.com/library/weekly/aa062400.htm
"À" with cities: "à Paris", "à Orléans", "à New York", "à Athènes".
"En" with all feminine countries and the ones beginning with a vowel: "en Angleterre", "en France", "en Espagne", "en Iran", "en Uruguay".
"Au" with masculine countries beginning with a consonant: "au Brésil", "au Mexique", "au Sénégal", "au Maroc".
"Aux" with plural countries: "aux États Unis", "aux Pays-Bas", "aux Maldives".
They use different forms depending on city, state, country and continent also gender. En is for going TO a place that is a feminine country and à is for cities i don't think that gender matters for cities, but i could be wrong on that part. His link probably leads you to a graph or examples of the different usages depending on terms i listed above.
Don't people ever say vers Paris anymore? Is that phrase now archaic?
"vers" (toward) Paris means that your are heading in Paris' direction, not that you will ever get there.
This type of liaison between a verb and a preposition is technically allowed, but is apparently very rare / denotes a high register. https://www.lawlessfrench.com/pronunciation/optional-liaisons/