How to tell if a grammar is LALR(1) formally?
The answer to your first question is: Not that we know of.
A grammar is $\hbox{LALR}(k)$ if and only if its $\hbox{LALR}(k)$ automaton is deterministic. The only way that we know of checking that a grammar is $\hbox{LALR}(k)$ is to build the automaton, or something that essentially amounts to building the automaton.
The good news is that the key complication is empty derivations. So, for example, if a $\hbox{LL}(1)$ grammar has no nonterminals that have only empty derivations (i.e. if every nonterminal has at least one non-empty derivation), it is $\hbox{LALR}(1)$.
See Beatty, On The Relationship Between LL(1) And LR(1) Grammars for further results. You may find something in there that's useful to you.